High bulk TAD with bottom of pocket support strands

Abstract

A papermaking fabric having a paper side (PS) and a machine side (MS) and being formed of a system of MD yarns interwoven with a first system of CD yarns, including first CD yarns, in a fabric weave pattern, with the fabric body including a plurality of pockets. The pockets have MD edges defined on first and second sides by floats / knuckles of one of the MD yarns and a next adjacent MD yarns, and first and second ends defined by a portion of a float or knuckle of a middle one of the MD yarns over first and second pocket end ones of the first CD yarns. At least 3 adjacent ones of the first CD yarns between the pocket end ones of the first CD yarns extend over the middle one of the MD yarns between the first and second sides. A second system of CD yarns is interwoven with the system of MD yarns, and includes second CD yarns arranged alternating with first CD yarns. At least two consecutive ones of the second CD yarns are arranged over the middle one of the MD yarns between the first and second pocket end ones of the first CD yarns. The second CD yarns reduce the amount of open spaces in the bottoms of the pockets.

Description

HIGH BULK TAD WITH BOTTOM OF POCKET SUPPORT STRANDSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No.63 / 691 ,032, filed September 5, 2024 the contents of which are incorporated herein by reference.TECHNICAL FIELD

[0002] The invention concerns fabrics for use in a papermaking process. The invention more specifically relates to through-air drying (TAD) fabrics.BACKGROUND

[0003] Papermaking fabrics are used to trap and / or support fibers during formation of paper from a slurry of cellulose and other fibers. Some papermaking fabrics are woven in one or more layers and include machine direction (MD) and cross-machine direction (CD) yarns, which may be monofilaments or multi-filaments that are interwoven in a repeating pattern. Papermaking fabrics may be woven endlessly to form a belt, or may be flat woven and have the ends seamed or joined together to form a belt.

[0004] For certain applications of papermaking fabrics, such as for tissue making, through air drying (TAD) is used to dry the nascent paper web using hot air that is drawn or pulled through the paper web being formed as it is carried around a roll by a TAD papermaking fabric belt. TAD arrangements avoid compaction of the fibers that occurs in the conventional press section of a papermaking machine, retaining the bulk of the paper (tissue) web during drying. TAD fabrics generally have a 3-dimensional form defined by the weave that is adapted to maximize the amount of sheet molding that occurs on the TAD fabric. This is used to increase the apparent bulk of the web, which is important for tissue making.

[0005] Figures 1 and 2 show, respectively, a weave diagram and a PS surface of a prior art TAD papermaking fabric 30. MD yarns are indicated as 21 - 28 along the top of the weave diagram in Figure 1 , and CD yarns are indicated as 1 , 3, 5, 7, 9, 11 , 13, 15 on the left side for a single repeat of the weave pattern (note that CD yarn numbering as 1 , 3, 5, 7, 9, 11 , 13, 15 is being used specifically for comparison purposes to the present invention, and the conventional numbering used for this prior art fabric would be CD yarns 1 - 8). The ovals19300352.1indicated as 32 represent pockets formed by the weave pattern that increase the apparent bulk of the web of tissue or other paper product formed by the TAD papermaking fabric 30. The dark areas 34 indicate where the “bottom” of the pockets created by the respective CD and MD yarns have openings or holes due to the weave pattern, and the CD and MD yarn shapes and sizes selected.

[0006] While known TAD papermaking fabrics are satisfactory in many respects, there have been issues with the formation of pin holes in the paper sheet.

[0007] It would be desirable to provide an improved papermaking fabric for TAD as well as other applications to address this issue.SUMMARY

[0008] The inventors have determined that the pin hole formation in the web formed on the known TAD fabrics is based in part on the open areas at the bottoms of the pockets, which can result in unsatisfactory product.

[0009] In order to address this, in one aspect, a papermaking fabric, and more particularly a TAD fabric, for a papermaking machine is provided with the fabric including a fabric body having a paper side (PS) and a machine side (MS) and being formed of a system of MD yarns interwoven with a first system of CD yarns, including first CD yarns, in a fabric weave pattern, with the fabric body including a plurality of pockets. Each of the pockets have MD edges defined on a first side by a continuous PS MD yarn float of one of the MD yarns over at least 3 adjacent ones of the first CD yarns, and on a second side by an MD yarn knuckle of a next adjacent one of the MD yarns over a single one of the first CD yarns and a portion of an MD yarn float over more than one of the first CD yarns of the next adjacent one of the MD yarns. On a first end each of the pockets is defined by a portion of a float or knuckle of a middle one of the MD yarns between the one MD yam and the next adjacent MD yarn over a first pocket end one of the first CD yarns that is adjacent to the at least 3 adjacent ones of the first CD yarns that extend under the continuous PS MD yarn float and on a second end by a portion of a float or knuckle of the middle one of the MD yams between the one MD yarn and the next adjacent MD yam over a second pocket end one of the first CD yarns that is adjacent to the at least 3 adjacent ones of the first CD yams that extend under the continuous PS MD yarn float, and bottoms of the pockets being defined in part by the middle one of the MD yams extending under the at least 3 adjacent ones of the first CD yarns as well as the at least 3 adjacent ones of the first CD yarns between the first and second pocket sides. A29300352.1second system of CD yarns is interwoven with the system of MD yarns, with the second system of CD yarns including second CD yarns arranged alternating with first CD yarns, and at least two consecutive ones of the second CD yarns are arranged over the middle one of the MD yarns between the first pocket end one of the first CD yarns and the second pocket end one of the first CD yarns. This second system of CD yams reduces the amount of open spaces in the bottoms of the pockets, and also has the effect of elongating the pockets in the MD.

[0010] In one embodiment, the second CD yams have a smaller cross-section than the first CD yarns. For example, the first CD yarns can have a diameter of 0.45mm - 0.75 mm, and the second CD yarns can have a diameter of 0.25 mm to 0.75 mm. The MD yarns can have a width of 0.25 mm to 0.50 mm. However, the specific sizes can vary depending on the application.

[0011] In one embodiment, each pocket bottom includes 3 of the first CD yams that are located alternately with 2 of the second CD yarns.

[0012] In one embodiment, each of the first CD yams passes in sequence over 2, under 1 , over 1 , under 1 , over 1 under 2 of the MD yarns in each repeat. However, this arrangement can be varied depending on the particular arrangement.

[0013] In one embodiment, each of the second CD yarns passes in sequence under 4, over 1 , under 2, over 1 of the MD yarns in each repeat. However, this arrangement can be varied depending on the particular arrangement.

[0014] In one embodiment, a through space of the fabric (i.e. , the open areas or holes in a direction normal to the PS) as a percentage of an overall area of the fabric is less than about 10% when viewed in a plan view from the PS, and preferably is less than 10%, and more preferably is less than 9%. In one embodiment the through space is about 8%.

[0015] In one preferred arrangement, the fabric weave pattern includes 8 of the MD yarns, 8 of the first CD yarns, and 8 of the second CD yarns in each repeat of the fabric weave pattern.

[0016] A cross-sectional shape of the yarns can vary, and at least some of the MD yarns or the CD yams may be selected from: generally circular, ovate, elliptical, square or rectangular.39300352.1

[0017] In one embodiment, the MD yarns, the first CD yarns, and the second CD yarns are made from at least one material selected from PET, PA, PBT, PEN, PPS or PEEK. However, other material may be used depending on the particular application.

[0018] Preferably, an average open frame size of the holes or openings in the fabric according to the disclosure, when viewed in a direction normal to a paper side surface, is less than about 6.0E-02 mm2.

[0019] Further, preferably, a number of holes per cm2 in in the fabric according to the disclosure, when viewed in a direction normal to a paper side surface, is at least about 168.

[0020] In another aspect, the present disclosure provides a papermaking fabric for a papermaking machine, with the fabric including a fabric body including a paper side (PS) and a machine side (MS) and being formed of a system of MD yarns interwoven with a first system of CD yarns, including first CD yarns, in a fabric weave pattern, with the fabric body including a plurality of pockets. A second system of CD yarns is interwoven with the system of MD yarns, and the second system of CD yarns includes second CD yarns arranged alternating with first CD yarns. The second CD yarns are arranged to only form part of the MS and only extend partially into the body of the fabric and do not extend to the PS. This arrangement provides more support for the fibers that coalesce at the bottoms of the pockets that are defined by the system of MD yarns and the first system of CD yarns.

[0021] In one embodiment, each of the second CD yarns passes in sequence under 4, over 1 , under 2, and over 1 of the MD yarns in each repeat, such that internal knuckles formed by the over 1 weave of the second CD yams over ones of the MD yarns are held below the PS via adjacent ones of the MD yarns to the internal knuckles.

[0022] Using one or more of the above features to add support to the bottoms of pockets helps to bridge the openings in the prior art TAD fabric, providing better paper web / fiber support and reducing the tendency for pin holing

[0023] Fabrics made in accordance with the teachings of the invention will be heatset, processed, seamed, and finished in a manner using techniques and equipment similar to that used with other known TAD fabrics.BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The foregoing summary as well as the following detailed description will be best understood when read in conjunction with the appended drawings. In the drawings:49300352.1

[0025] Figure 1 is a weave diagram of a prior art papermaking fabric, and more specifically a TAD fabric, with certain areas designated as pockets being represented with ovals that are used to maximize the amount of sheet molding and increase the apparent bulk of a web, for example, tissue, being formed.

[0026] Figure 2 is a view of the PS of the prior art fabric according to the weave diagram shown in Figure 1 .

[0027] Figure 3 is a weave diagram of a papermaking fabric, and more specifically a TAD fabric, in accordance with the present disclosure which includes a second system of CD yarns interwoven with the system of MD yarns in order to reduce the amount of open spaces at the bottoms of the pockets, also schematically designated in the weave diagram with oval shapes.

[0028] Figure 4 is a PS view of a papermaking fabric in accordance with the present disclosure with the second set of CD yarns being indicated and showing the reduction of open spaces in the bottom of the pockets in comparison to the prior art fabric shown in Figure 2.

[0029] Figure 5 is a MS view of the fabric in accordance with the present disclosure shown in Figure 4 which more clearly shows the second system of CD yams.

[0030] Figure 6 is a PS view of a portion of the PS side of the papermaking fabric of Figure 4 showing an enlarged view of one of the pockets with specific features of one of the pockets identified with element numbers which would apply similarly to the other pockets as would be understood by a person skilled in the art.

[0031] Figure 7 is a PS view of a second embodiment of a papermaking fabric, and more specifically a TAD fabric, in accordance with the present disclosure including the second system of CD yarns for closing spaces at the bottoms of the pockets woven with an 8 shed pattern.

[0032] Figures 8A and 8B show the steps of an image analysis method used to calculate overall open space per unit area and a number of the individual open spaces or holes per unit area of the papermaking fabric in accordance with the present disclosure.

[0033] Figures 9A and 9B show the steps of an image analysis method used to calculate overall open space per unit area and a number of the individual open spaces or holes per unit area of the prior art papermaking fabric.

[0034] Figure 10 is a PS view of a third embodiment of a papermaking fabric, and more specifically a TAD fabric, in accordance with the present disclosure including the second59300352.1system of CD yarns for closing spaces at the bottoms of the pockets woven with a 10 shed pattern

[0035] Figure 11 is a PS view of a fourth embodiment of a papermaking fabric, and more specifically a TAD fabric, in accordance with the present disclosure including the second system of CD yarns for closing spaces at the bottoms of the pockets woven with a 12 shed pattern.DETAILED DESCRIPTION

[0036] Certain terminology is used in the following description for convenience only and is not limiting. The fabric according to the invention is an industrial textile, preferably a papermaking fabric, and more preferably a TAD fabric. However, in some embodiments it can have many industrial applications, such as conveyor belts, etc., and could also, for example, be used in spunbound and spunlace applications The fabrics of the present disclosure are woven. The words "paper side" or “(PS)” and "machine side" or “(MS)” designate surfaces of the fabric with reference to their use in one preferred application in papermaking; however, these terms merely represent first and second or upper and lower surfaces of the planar fabric. “Yam” is used to generically identify a monofilament or multifilament fiber. “Warp” and “weft” are used to designate yarns or monofilaments based on their position in the loom that extend in perpendicular directions in the fabric and either could be a machine direction (MD) or crossmachine direction (CD) yarn in the fabric once it is installed on a piece of equipment, depending on whether the fabric is, for example, flat woven or continuously woven. In one preferred arrangement, the fabric can be flat woven and seamed at the warp ends in order to form a continuous belt, so that the warp yarns are MD yarns and the weft yarns are CD yarns. The base fabric could also be continuously woven, in which case, the weft yarns would extend in the MD and the warp yarns would extend in the CD. The base fabric could also be a multiaxial fabric assembled from a strip of fabric having a narrower width that is wound around two spaced-apart rolls at an angle to the MD, with the longitudinal edges being joined together to form a wider fabric belt. For the multiaxial arrangement, the MD and CD yarns may be canted with respect to a true MD and a true CD by about 1 ° to 7 °. However, for this disclosure, this is encompassed within the reference to MD and CD yarns. Regardless of how the base fabric is made, the designations of warp, weft and / or MD and CD as used in the description that follows can be interchanged. The terms “about” and “approximately” are to be construed by significant digits (i.e., about 10% would include 9.5% to 10.4%).69300352.1

[0037] Referring to Figures 3-6, a papermaking fabric 40, and more preferably a forming fabric or TAD fabric 40, for a papermaking machine is shown. The fabric 40 includes a fabric body 41 having a paper side (PS - see Figure 4) and a machine side (MS - see Figure 5) and being formed of a system of MD yarns 42, which include MD yarns 21 -28, that are interwoven with a first system of CD yarns 44, including first CD yarns 1 , 3, 5, 7, 9, 11 , 13, and 15, in a fabric weave pattern. The weave pattern is illustrated via the weave diagram shown in Figure 3 and is an 8 shed pattern. However, other numbers of sheds can be used in the weave pattern. The fabric body 41 includes a plurality of pockets 50, indicated schematically in the weave diagram of Figure 3 and generally indicated in Figure 4 via ovals in the defined area, with a representative example being more specifically shown in Figure 6 with respect to a single pocket 50 which can be better understood along with the explanation of how each pocket 50 is defined.

[0038] Still with reference to Figures 3-6, each of the pockets 50 includes MD edges defined on a first side 50a (see Figure 6) by a continuous PS MD yarn float, one example indicated at 26f in Figure 6 and apparent from the weave diagram in Figure 3 as well as the PS view of the fabric 40 in Figure 4 for all of the pockets 50, where the MD yarn 26 extends over adjacent ones of the first CD yarns 7, 9, 11. The first side 50a PS MD yarn float 26f that is explicitly called out in Figure 6, as well as the other first side PS MD yarn 21 - 28 floats (indicated in the weave diagram in Figure 3 by the filled in boxes and apparent in Figure 4) extend over at least three adjacent ones of the first CD yarns 1 , 3, 5, 7, 9, 11 , 13, 15. The second side 50b of the pocket 50 is defined by at least one MD yarn knuckle, 24k shown in Figure 6, of a next adjacent one of the MD yarns ( MD yarn 24 in the example shown in Figure 6) that extends over a single one of the first CD yarns (first CD yarn 7 in the example shown in Figure 6) as well as a portion of an MD yarn float (MD yarn float 24f in the example shown in Figure 6) over more than one of the first CD yarns (first CD yarns 3, 5, 7 in the example shown in Figure 6), with the float over the CD yarn 7 in Figure 6, of the next adjacent one of the MD yams 24 forming the remainder of the second side 50b of the pocket 50 shown in detail in Figure 6. For the example pocket shown in Figure 6, a first end 50c of the pocket 50 is formed by a portion of a float 25f or a knuckle 25k (the knuckle 25k is shown) of a middle one of the MD yarns 25 between the one MD yarn 26 and the next adjacent MD yarn 24 over a first pocket end one of the first CD yarns 5 that is adjacent to the at least three adjacent ones of the first CD yams 7, 9, 11 that extend under the continuous PS MD yam float 26f, and79300352.1on a second end 50d by a portion of a float 25f or knuckle 25k (the float 25f is shown) of the middle one of the MD yarns 25 between the one MD yarn 26 and the next adjacent MD yarn 24 over a second pocket end one of the first CD yarns 13 that is adjacent to the at least three adjacent ones of the first CD yarns 7, 9, 11 under the continuous PS MD yarn float 26f that defines the first side 50a of the pocket 50. The bottoms of the pockets 50 are defined in part by the middle one of the MD yarns 25 between the one MD yarns 26 and the next adjacent MD yarns 24 that extends under the at least three adjacent ones of the first CD yarns 7, 9, 11 as well as the at least three adjacent ones of the first CD yarns 7, 9 ,11 between the first and second sides 50a, 50b.

[0039] While the above description is specifically with respect to the one pocket 50 that is shown in detail in Figure 6, it would apply similarly to the other pockets 50 within the weave repeat with respect to the specific MD yarns 21 - 28 and first CD yarns 1 , 3, 5, 7, 9, 11 , 13,15 that surround the respective pockets 50 as would be understood by a person of ordinary skill in the art based on the weave diagram shown in Figure 3 and the PS view of the fabric 40 shown in Figure 4 where the pockets 50 are identified.

[0040] In order to reduce the amount of open space at the bottoms of the pockets 50, a second system 46 of CD yarns, are interwoven with the system 42 of MD yarns 21 -28, with the second system 46 of CD yarns including second CD yarns 2, 4, 6, 8, 10, 12, 14, 16 that are arranged alternating with the first CD yarns 1 , 3, 5, 7, 9, 11 , 13, 15, in a single repeat, with at least two consecutive ones of the second CD yarns 2, 4, 6, 8, 10, 12, 14, 16 being arranged over the middle one of the MD yarns 21 -28 between the first pocket end 50c one of the first CD yarns (first CD yarn 5 for the pocket 50 indicated in Figure 6) and the second pocket end 50d one of the first CD yarns (first CD yarn 13 for the pocket 50 indicated in Figure 6). For the pocket 50 specifically labeled in Figure 6, the first pocket end 50c one of the first CD yarns is first CD yarn 5, and the second pocket end 50d one of the first CD yarns is first CD yarn 13. The two consecutive ones of the second CD yarns 8, 10 are arranged alternating with the first CD yarns 7, 9, 11 over the middle one of the MD yams 25 to close more of the open spaces in the bottom of the pocket 50. This also elongates the pockets 50 in comparison to the pockets 32 of the prior art due to the additional second CD yarns 2, 4, 6, 8, 10, 12, 14, 16, and the bottoms of the pockets are formed with 5 of the CD yarns 1 - 16.

[0041] Further, the CD yarns 2, 4, 6, 8, 10, 12, 14, 16 of the second system of CD yarns 44 that are on the pocket side of the CD yarns 1 , 3, 5, 7, 9, 11 , 13, 15 of the first system of89300352.1CD yarns 42 that form the first and second ends 50c, 50d of each pocket 50 (for example first CD yarns 5, 13 in Figure 6) also reduce the amount of open space in the fabric body 41 between the first and second ends 50c, 50d even if they extend under the middle one of the MD yarns 21 -28 (for example, second CD yarns 6, 12 in Figure 6) between the first pocket end 50c one of the first CD yarns 1 , 3, 5, 7, 9, 11 , 13, 15 (first CD yarn 5 for the pocket 50 indicated in Figure 6) and the second pocket end 50d one of the first CD yarns 1 , 3, 5, 7, 9, 11 , 13, 15 (first CD yarn 13 for the pocket 50 indicated in Figure 6). This further contributes to the reduced open spaces (or holes) 48 in the overall fabric.

[0042] Those skilled in the art will understand that Figure 6 has one specific pocket 50 indicated and labeled, and that the two consecutive ones of the second CD yarns 2, 4, 6, 8, 10, 12, 14, 16 would be the respective ones indicated for the other pockets based on the weave diagram shown in Figure 3 as well as the PS view of the fabric 40 shown in Figure 4 where it is apparent which of the second CD yarns 2, 4, 6, 8, 10, 12, 14, 16 are used in each specific pocket 50 within a weave repeat.

[0043] In a preferred arrangement, the second CD yarns 2, 4, 6, 8, 10, 12, 14, 16 have a smaller cross-section than the first CD yarns 1 , 3, 5, 7, 9, 11 , 13, 15. For example, the first CD yarns may have a diameter of 0.45 mm - 0.75 mm, and the second CD yarns can have a diameter of 0.25 mm to 0.75 mm. The MD yarns 21 -28 may be round in cross-section or may have a flattened cross-section in a thickness direction of the fabric 40 and can have a width of 0.25 mm to 0.50 mm. However, those skilled in the art will recognize that other sizes can be used. While diameters are noted, it is also possible for either the CD yams 1 -16 and / or the MD yarns 21 -28 to have cross-sections that are other than circular, such as oblong or rectangular.

[0044] In the illustrated embodiment, each pocket 50 has a bottom that includes three of the first CD yarns 1 , 3, 5, 7, 9, 11 , 13, 15 that are located alternately between two of the second CD yarns 2, 4, 6, 8, 10, 12, 14, 16. However, other arrangements could be provided.

[0045] In the illustrated arrangement, each of the second CD yarns 2, 4, 6, 8, 10, 12, 14, 16 passes in sequence under four, over one, under two, over one of the MD yarns 21 -28 in each repeat of the fabric weave pattern. However, other weave patterns could be provided.

[0046] In the illustrated embodiment, the fabric weave pattern includes 8 of the MD yarns 21-28, 8 of the first CD yarns, 1 , 3, 5, 7, 9, 11 , 13, 15, and 8 of the second CD yarns 2,99300352.14, 6, 8, 10, 12, 14, 16 in each repeat of the fabric weave pattern. However, other weave patterns with a different number of yarns in each repeat could be used.

[0047] The cross-sectional shape of at least some of the MD yarns 21-28 and / or the CD yarns 1 -16 can be selected for one or more of generally circular, ovate, elliptical, square, or rectangular.

[0048] The MD yarns 21 -28, the first CD yarns 1 , 3, 5, 7, 9, 11 , 13, 15 as well as the second CD yarns 2, 4, 6, 8, 10, 12, 14, 16 are preferably made from at least one material selected from PET, PA, PDT, PEN, PPS, or PEEK. However, other suitable materials may be used depending on the particular application.

[0049] Referring again to Figure 3, the weave diagram shows MD yarn 21 passing under CD yarns 1 -3, over CD yarns 4 - 10, under CD yarn 11 , over CD yarns 12-14, and under CD yarns 15-16, with the pocket 50 being formed where the MD yarn 21 passes under CD yarns 15, 16, and under CD yarns 1 -3 of the next repeat.

[0050] MD yarn 22 is shown in Figure 3 as passing over CD yarns 1 -4, under CD yarn5, over CD yarns 6-8, under CD yarns 9-13, and over CD yarns 14-16, with the pocket 50 being formed where the MD yarn 22 passes under CD yarns 9-13.

[0051] Still with reference to Figure 3, MD yarn 23 is shown passing over CD yarns 1 - 2, under CD yarns 3-7, over CD yarns 8-14, under CD yarn 15, and over CD yarn 16. Here, the pocket 50 is formed where MD yarn 23 passes under CD yarns 3-7.

[0052] Still with reference to Figure 3, MD yarn 24 is shown passing under CD yarn 1 , over CD yarns 2-8, under CD yarn 9, over CD yarns 10-12, and under CD yarns 13-16, with the pocket 50 being formed where MD yarn 24 passes under CD yarns 13-16, and under CD yarn 1 of the next repeat.

[0053] With respect to MD yam 25, this is shown in Figure 3 as passing over CD yarns 1 -2, under CD yarn 3, over CD yarns 4-6, under CD yarns 7-11 , and over CD yarns 12-16. The pocket is formed where MD yarn 25 passes under CD yarns 7-11 .

[0054] Still with reference to Figure 3, MD yam 26 is shown as passing under CD yams 1 -5, over CD yams 6-12, under CD yarn 13, and over CD yarns 14-16, with the pocket 50 being formed where MD yarn 27 passes under CD yarns 1 -5.

[0055] Still with reference to Figure 3, MD yarn 27 is shown passing over CD yarns 1 -6, under CD yarn 7, over CD yarns 8-10, under CD yarns 11-15, and over CD yarn 16, with the pocket 50 being formed where MD yarn 27 passes under CD yarns 11 -15.109300352.1

[0056] Still with reference to Figure 3, MD yarn 28 is shown passing under CD yarn 1 , over CD yarns 2-4, under CD yarns 5-9, and over CD yams 10-16, with the pocket 50 being formed where CD yarn 28 passes under CD yarns 5-9.

[0057] While a specific embodiment is shown in Figures 4-6 in which the MD yarns 21 - 28 have a diameter of about 0.40 mm and the first system of CD yams 1 , 3, 5, 7, 9, 11 , 13, 15 have a diameter of about 0.55 mm, and the second system CD yarns 2, 4, 6, 8, 10, 12, 14, 16, have a diameter of about 0.40 mm, other the sizes and shapes could be used.

[0058] For example, Figure 7 shows the PS of a second embodiment of a papermaking fabric 40’ that includes the fabric body 41 '. Here the first system of MD yarns indicated at 42 are formed with an oval cross-section having a thickness of 0.354 mm and a width of 0.40 mm. The first system of CD yarns indicated at 44 have a diameter of 0.55 mm, and the second system CD yarns indicated at 46 have a diameter of 0.40 mm. The arrangement of the MD yams and the first and second systems of CD yarns are the same as shown in the weave diagram in Figure 3. With this arrangement, the wider aspect ratio of the system of MD yarns 42 also provides better coverage at the bottoms of the pockets.

[0059] Based on this arrangement, the ratio of through space or holes 48 in the fabric 40 as a percentage of an overall area of the fabric 40 is less than about 10% when viewed in a plan view from the PS, as shown in Figures 4 and 6. Preferably, the ratio of through space or holes 48 to overall area is less than 10%, and more preferably is less than 9%. In the illustrated embodiment of the fabric 40, the ratio of through space or holes 48 to overall area is less than 8%. In comparison with Figure 2 showing the prior art arrangement of the fabric 30 which does not include the second system of CD yarns 46, the present arrangement can provide a reduction in the ratio of through space or holes 48 to overall area which can be 5% or more, more preferably 10% or more, and in the illustrated embodiment, a reduction on the order of 25% is achieved in comparison to the prior art fabric 30.

[0060] Additionally, the number of individual through spaces or holes 48 in the fabric 40 per unit area when viewed in a direction normal to the PS is also increased in comparison to the prior art fabric 30. Preferably, the number of individual through spaces or holes 48 in the papermaking fabric 40 is 120% or greater per unit area in comparison to the prior art fabric 30. More preferably, the number of individual through spaces or holes 48 in the papermaking fabric 40 is 130% or greater per unit area in comparison to the prior art fabric 30. In the119300352.1illustrated embodiment of the fabric 40, the number of individual through spaces or holes 48 in the papermaking fabric 40 is about 135% of that of the prior art fabric 30.

[0061] Referring to Figures 8A, 8B, 9A, and 9B, a method for calculating the ratio of through space or holes 48 in the fabric 40 as a percentage of an overall area of the fabric 40 will be explained. First, a unit area of the fabric 40 is scanned. In one example, a Micro-CT scan is taken of a unit area that is 10mm x 10mm of fabric 40. The raw image data can be captured using a 10um voxel SkyScan 1273 scanner to capture raw image data. The raw image data is then reconstructed into cross-sectional images. This can be done, for example, via 3D STL models generated from 2D data.

[0062] Next, 3D STL file is opened using an imaging program, such as Digital Surf MountainsMap software, in order to extract the surface such as shown in Fig. 8A, where the projected open areas or holes 48 are distinguished from the MD yarns 21-28 and the CD yams 1 -16. From this, a slice study is created, and thresholds are used to calculate projected open area.

[0063] Further, a studiable image can be exported from the imaging program, such as the noted MountainMap software, and image file is then opened using image analysis software, such as Imaged. As shown in Fig. 8b, the open areas or holes 48 may be treated as particles, and the mean particle size and number for the 10mm x 10mm fabric area can be calculated.

[0064] For Figs. 8A and 8B, which show a portion of the fabric 40, this resulted in a calculated Open Area (i.e. , through space) of 8.0%, an average Open Frame Size of the holes 48 of 4.29E-02 mm2, and a number of Open Frames (i.e., holes 48) / cm2of 189. Based on the data reviewed, an average open frame size of holes 48 in the fabric 40 when viewed in a direction normal to a paper side surface is preferably in a range of 6.0E-02 mm2or less. Further, a number of holes 48 per cm2in the fabric 40 when viewed in a direction normal to a paper side surface is at least about 168.

[0065] Figs. 9A and 9B show the same data for the prior art fabric 30, where the resulting data that was calculated is an Open Area of 10.2%, an average Open Frame Size of 7.39E-02 mm2, and a number of Open Frames / cm2of 140.

[0066] This demonstrates the increase in the number of Open Frames per unit area, reduced overall Open Area, as well as reduced average Open Frame Size for the fabric 40129300352.1according to the present disclosure, all of which contribute to the enhanced performance and reduction in pinholes being formed on a tissue or paper web that is carried by the fabric 40.

[0067] Referring again to Figs. 4 and 5, in another aspect, the present disclosure provides a papermaking fabric 40 for a papermaking machine, with the fabric 40 including a fabric body 41 having a paper side (PS) and a machine side (MS) and being formed of a system of MD yarns 42, including MD yarns 21 -28, interwoven with a first system of CD yarns 44 including first CD yarns 1 , 3, 5, 7, 9, 11 , 13, 15, in a fabric weave pattern, such as noted above, with the fabric body 41 including a plurality of pockets 50 on the PS. A second system of CD yarns 46 is interwoven with the system of MD yarns 42, and the second system of CD yarns 46 includes second CD yarns 2, 4, 6, 8, 10, 12, 14, 16 arranged alternating with first CD yarns 1 , 3, 5, 7, 9, 11 , 13, 15. The second CD yarns 2, 4, 6, 8, 10, 12, 14, 16 are arranged to only form part of the MS and only extend partially into the body 41 of the fabric 40 and do not extend to the PS. This arrangement provides more support for the fibers that coalesce at the bottoms of the pockets 50 that are defined by the system of MD yarns 42 and the first system of CD yarns 44.

[0068] As shown in Fig. 5, in one embodiment, each of the second CD yarns 2, 4, 6, 8, 10, 12, 14, 16 passes in sequence under 4, over 1 , under 2, and over 1 of the MD yarns 21 - 28 in each repeat, such that internal knuckles 54 (indicated in Fig. 4) formed by the over 1 weave of the second CD yarns 2, 4, 6, 8, 10, 12, 14, 16 over ones of the MD yarns 21 -28 are held below the PS via adjacent ones of the MD yarns 21-28 to the respective internal knuckles 54. Preferably, the internal knuckles 54 are located only in the bottoms of the pockets 50.

[0069] This arrangement of additional CD support yarns in the form of the second system of CD yarns 46 provides extra support for improved handling and formation of paper or tissue products.

[0070] Referring now to Figure 10, a third embodiment of a papermaking fabric 40” that includes the fabric body 41” is shown. The third embodiment of the papermaking fabric 40” is similar to the second embodiment 40’, except that it is woven with a 10 shed pattern. Here the first system of MD yarns is indicated at 42, and may have a round, oval or other crosssection, and can be, for example, formed with an oval cross-section having a thickness of 0.354 mm and a width of 0.40 mm. The first system of CD yarns indicated at 44 may have a round, oval or other cross-section, and can be, for example, formed with a round cross-section have a diameter of 0.55 mm, and the second system CD yarns indicated at 46 may have a139300352.1round, oval or other cross-section, and can be, for example, formed with a round cross-section have a diameter of 0.40 mm. Based on the 10 shed weave pattern, there are 10 MD yarns 42, 10 CD yarns 44 in the first system of CD yarns, and 10 of the CD yarns 46 of the second system of CD yarns. In the illustrated arrangement, each of the second CD yarns 46 passes in sequence under 3, over 1 , under 2, over 1 , under 2, and over 1 of the MD yams 42 in each repeat. This arrangement reduces the projected open area at the bottoms of the pockets and also increases the number of holes 48. Further, the wider aspect ratio of the system of MD yams 42 also provides better coverage at the bottoms of the pockets.

[0071] Referring now to Figure 11 , a fourth embodiment of a papermaking fabric 40”’ that includes the fabric body 4T” is shown. The fourth embodiment of the papermaking fabric 40”’ is similar to the second embodiment 40’, except that it is woven with a 12 shed pattern. Here the first system of MD yarns is indicated at 42, and may have a round, oval or other cross-section, and can be, for example, formed with an oval cross-section having a thickness of 0.354 mm and a width of 0.40 mm. The first system of CD yarns indicated at 44 may have a round, oval or other cross-section, and can be, for example, formed with a round crosssection have a diameter of 0.55 mm, and the second system CD yarns indicated at 46 may have a round, oval or other cross-section, and can be, for example, formed with a round crosssection have a diameter of 0.40 mm. Based on the 12 shed weave pattern, there are 12 MD yarns 42, 12 CD yarns 44 in the first system of CD yarns, and 12 of the CD yarns 46 of the second system of CD yarns. In the illustrated arrangement, each of the second CD yarns 46 passes in sequence under 4, over 1 , under 1 , over 1 , under 2, over 1 , under 1 , over 1 of the MD yarns 42 in each repeat. This arrangement also reduces the projected open area at the bottoms of the pockets and also increases the number of holes 48. Further, the wider aspect ratio of the system of MD yarns 42 also provides better coverage at the bottoms of the pockets.

[0072] Having thus described the present invention in detail, it is to be appreciated and will be apparent to those skilled in the art that many physical changes, only a few of which are exemplified in the detailed description of the invention, could be made without altering the inventive concepts and principles embodied therein. It is also to be appreciated that numerous embodiments incorporating only part of the preferred embodiment are possible which do not alter, with respect to those parts, the inventive concepts and principles embodied therein. The present embodiment and optional configurations are therefore to be considered149300352.1in all respects as exemplary and / or illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all alternate embodiments and changes to this embodiment which come within the meaning and range of equivalency of said claims are therefore to be embraced therein.9300352.1

Claims

CLAIMS1 . A papermaking fabric for a papermaking machine, the fabric comprising: a fabric body including a paper side (PS) and a machine side (MS) and being formed of a system of MD yarns interwoven with a first system of CD yarns, including first CD yarns, in a fabric weave pattern, the fabric body including a plurality of pockets; each of the pockets have MD edges defined on a first side by a continuous PS MD yarn float of one of the MD yarns over at least 3 adjacent ones of the first CD yarns, and on a second side by at least one MD yarn knuckle of a next adjacent one of the MD yarns over a single one of the first CD yarns and a portion of an MD yarn float over more than one of the first CD yarns of the next adjacent one of the MD yarns, and on a first end by a portion of a float or knuckle of a middle one of the MD yarns between the one MD yarn and the next adjacent MD yarn over a first pocket end one of the first CD yarns that is adjacent to the at least 3 adjacent ones of the first CD yarns under the continuous PS MD yarn float and on a second end by a portion of a float or knuckle of the middle one of the MD yarns between the one MD yarn and the next adjacent MD yarn over a second pocket end one of the first CD yarns that is adjacent to the at least 3 adjacent ones of the first CD yarns under the continuous PS MD yam float, and bottoms of the pockets being defined in part by the middle one of the MD yarns extending under the at least 3 adjacent ones of the first CD yarns as well as the at least 3 adjacent ones of the first CD yarns between the first and second pocket sides; a second system of CD yarns interwoven with the system of MD yams, the second system of CD yarns including second CD yarns arranged alternating with first CD yarns, and at least two consecutive ones of the second CD yarns are arranged over the middle one of the MD yarns between the first pocket end one of the first CD yarns and the second pocket end one of the first CD yarns.

2. The fabric according to claim 1 , wherein the second CD yarns have a smaller crosssection than the first CD yarns.

3. The fabric according to claim 1 , wherein each pocket bottom includes 3 of the first CD yarns that are located alternately between 2 of the second CD yarns.

4. The fabric according to claim 1 , wherein each of the second CD yarns passes in sequence under 4, over 1 , under 2, and over 1 of the MD yarns in each repeat.169300352.

15. The fabric according to claim 1 , wherein each of the second CD yarns passes in sequence under 3, over 1 , under 2, over 1 , under 2, and over 1 of the MD yarns in each repeat.

6. The fabric according to claim 1 , wherein each of the second CD yarns passes in sequence under 4, over 1 , under 1 , over 1 , under 2, over 1 , under 1 , over 1 of the MD yarns in each repeat.

7. The fabric according to claim 1 , wherein a through space of the fabric as a percentage of an overall area defined by the pocket is less than about 10% when viewed in a plan view from the PS.

8. The fabric according to claim 1 , wherein the fabric weave pattern includes 8 of the MD yarns, 8 of the first CD yarns, and 8 of the second CD yarns in each repeat.

9. The fabric according to claim 1 , wherein the fabric weave pattern includes 10 of the MD yarns, 10 of the first CD yarns, and 10 of the second CD yarns in each repeat.10 The fabric according to claim 1 , wherein the fabric weave pattern includes 12 of the MD yarns, 12 of the first CD yarns, and 12 of the second CD yarns in each repeat.11 . The fabric according to claim 1 , wherein a cross-sectional shape of at least some of the MD yarns or the CD yarns is selected from one of: generally circular, ovate, elliptical, square, or rectangular.

12. The fabric according to claim 1 , wherein the MD yams, the first CD yams, and the second CD yarns are made from at least one material selected from PET, PA, PBT, PEN, PPS, or PEEK.

13. The fabric according to claim 1 , wherein an average open frame size of holes in the fabric when viewed in a direction normal to a paper side surface is less than about 6.0E-02 mm2.179300352.

114. The fabric according to claim 1 , wherein a number of holes per cm2in in the fabric when viewed in a direction normal to a paper side surface is at least about 168.

15. A papermaking fabric for a papermaking machine, the fabric comprising: a fabric body including a paper side (PS) and a machine side (MS) and being formed of a system of MD yarns interwoven with a first system of CD yarns, including first CD yarns, in a fabric weave pattern, the fabric body including a plurality of pockets; a second system of CD yarns interwoven with the system of MD yarns, the second system of CD yarns including second CD yarns arranged alternating with first CD yarns, and the second CD yarns are arranged to only form part of the MS and only extend partially into the body of the fabric and do not extend to the PS.

16. The fabric of claim 15, wherein each of the second CD yarns passes in sequence under 4, over 1 , under 2, and over 1 of the MD yarns in each repeat, such that internal knuckles formed by the over 1 weave of the second CD yarns over ones of the MD yarns are held below the PS via adjacent ones of the MD yarns to the internal knuckles.

17. The fabric of claim 15, wherein each of the second CD yarns passes in sequence under3, over 1 , under 2, over 1 , under 2, and over 1 of the MD yarns in each repeat, such that internal knuckles formed by the over 1 weave of the second CD yarns over ones of the MD yarns are held below the PS via adjacent ones of the MD yarns to the internal knuckles.

18. The fabric of claim 15, wherein each of the second CD yarns passes in sequence under4, over 1 , under 1 , over 1 , under 2, over 1 , under 1 , over 1 the MD yarns in each repeat, such that internal knuckles formed by the over 1 weave of the second CD yarns over ones of the MD yarns are held below the PS via adjacent ones of the MD yarns to the internal knuckles.189300352.1

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