The present invention relates to the field of paper manufacturing. More particularly, the present invention relates to the manufacture of absorbent tissue products such as bath tissue, facial tissue, napkins, towels, wipers, cardboard, and the like. Specifically, the present invention relates to improved papermaking fabrics used to manufacture absorbent tissue products, methods of tissue manufacture, methods of fabric manufacture, and the actual tissue products produced thereby.
In the manufacture of tissue products, particularly absorbent tissue products, papermaking fibers are deposited onto forming wires and transferred as a newly-formed web to a transfer fabric, often with the aid of a vacuum box. From the transfer fabric, the web is then transferred to a through-air drying fabric to dry the web, which can provide the physical properties and the final product appearance to the web. There is a continuing need to improve web properties and machine operation by improving the transfer fabric. As an example, there is a need to improve the uniformity of the cross-direction (CD) strain in such transfer fabrics. There is also a need to improve through-air drying fabrics for improved operation of the machine as well as improved properties of the web and its visual appearance.
Some woven papermaking fabrics attempt to address some of these opportunities. For example, in traditional woven papermaking fabrics, topography in a transfer papermaking fabric was achieved by juxtaposing areas of tight weave of shute and warp filaments with areas of loose weave of shute and warp filaments that created unbalanced forces in the woven fabric to push long floats out of plane creating tight bundles of warp filaments. While this can provide varied topographies in the woven papermaking fabric, this technique provides some disadvantages, including, but not limited to: poor air permeability through the stacked warp filament bundles, limits on height of the topographical elements created by the warp filament bundles based on the number of warps that could be stacked (alternatively viewed as limits on pocket depth between topographical elements), difficulties in achieving uniformity of fiber support, aesthetic limitations, areas of excessive localized strain, creation of excessive pinholes especially in high cross-directional strain sheet contacting surfaces, and difficulties in weaving designs. Some of these disadvantages due to past woven papermaking fabric techniques can lead to deficiencies in the tissue being carried and produced on the papermaking fabric. For example, warp filament stacking can create areas of low basis weight in the base tissue sheet, decreased drying efficiency, and difficulties in tissue sheet release.
As such, there remains a need for articles of manufacture and methods of producing tissue products with improved physical properties without losses to tissue machine efficiency and productivity.
The present disclosure comprises paper manufacturing articles and processes that may satisfy one or more of the foregoing needs. For example, a paper manufacturing fabric of the present disclosure, when used as a transfer fabric in a tissue making process, produces an absorbent tissue web having improved paper properties and can result in improved manufacturing. The papermaking fabrics of the present disclosure could alternatively be used as through-air drying fabrics. Accordingly, the present disclosure is directed towards fabrics for manufacturing the absorbent tissue product, processes of making the absorbent tissue product, and processes of making the papermaking fabric.
Accordingly, in one aspect, a papermaking fabric is provided that includes a plurality of filaments, the plurality of filaments being woven together. The papermaking fabric can also include a machine contacting side and a web contacting side. The web contacting side can be opposite from the machine contacting side. The papermaking fabric can include at least one protuberance on the web contacting side of the papermaking fabric. The at least one protuberance can include a hollow internal pocket. The hollow internal pocket can include a height and a width.
In another aspect, a papermaking fabric can include a machine contacting side and a web contacting side. The papermaking fabric can include a first set of filaments including a first shrinkage property. The papermaking fabric can also include a second set of filaments including a second shrinkage property. The first shrinkage property can be different from the second shrinkage property. The first set of filaments and the second set of filaments can be woven and provide at least one protuberance on the web contacting side of the papermaking fabric. The at least one protuberance can define a hollow internal pocket.
In yet another aspect, a method of manufacturing a papermaking fabric comprising the steps of providing a plurality of warp filaments and a plurality of shute filaments for weaving, at least a portion of the plurality of warp filaments having a first shrinkage property and a portion of the plurality of shute filaments having a second shrinkage property, the first shrinkage property being different than the second shrinkage property; weaving the shute filaments and the warp filaments in a weave pattern to provide a woven fabric including a first machine direction end opposite from a second machine direction end and a machine contacting side opposite from a web contacting side; heating the first set of filaments and the second set of filaments after the plurality of shute filaments and the plurality of warp filaments are woven, wherein heating results in at least one protuberance having a hollow internal pocket; and seaming together the first and second machine direction ends of the woven fabric.
As used herein, the term “tissue product” refers to products made from tissue webs and includes, bath tissues, facial tissues, paper towels, industrial wipers, foodservice wipers, napkins, medical pads, medical gowns, and other similar products. Tissue products may comprise one, two, three or more plies.
As used herein, the terms “tissue web” and “tissue sheet” refer to a fibrous sheet material suitable for forming a tissue product.
As used herein, the term “papermaking fabric” means any woven fabric used for making a cellulosic web such as a tissue sheet, either by a wet-laid process or an air-laid process. Specific papermaking fabrics within the scope of this invention include forming fabrics; transfer fabrics conveying a wet web from one papermaking step to another, such as described in U.S. Pat. No. 5,672,248; as molding, shaping, or impression fabrics where the web is conformed to the structure through pressure assistance and conveyed to another process step, as described in U.S. Pat. No. 6,287,426; as creping fabrics as described in U.S. Pat. No. 8,394,236; as embossing fabrics as described in U.S. Pat. No. 4,849,054; as a structured fabric adjacent a wet web in a nip as described in U.S. Pat. No. 7,476,293; or as a through-air drying fabric as described in U.S. Pat. Nos. 5,429,686, 6,808,599 B2 and 6,039,838. The fabrics of the invention are also suitable for use as molding or air-laid forming fabrics used in the manufacture of non-woven, non-cellulosic webs such as baby wipes.
Fabric terminology used herein follows naming conventions familiar to those skilled in the art. For example, as used herein the term “warp (s)” generally refers to machine-direction yarns and the term “shute” generally refers to cross-machine direction yarns, although it is known that fabrics can be manufactured in one orientation and run on a paper machine in a different orientation.
As used herein, the term “protuberance” generally refers to a three dimensional element formed by one or more warp filaments overlaying a plurality of weft yarns. In certain embodiments the combination of the longitudinal spacing of the cross-direction floats in the first shute filaments, the first shute filaments having a higher shrinkage property than the second shute filaments, and high friction tying areas between the cross-direction floats allow the first shute filaments to shrink and cause the adjacent second shute filaments to buckle and form the protuberances on the web contacting side of the papermaking fabric after heat finishing.
As used herein the term “hollow,” with particular reference to protuberances, means that the protuberances contain an internal cavity or void region.
As used herein, the term “landing area” generally refers to a portion of the web contacting surface of the papermaking fabric lying between adjacent protuberances.
As used herein, the term “landing area plane” is defined by the top of the lowest visible yarn which a tissue web can contact when molding into a papermaking fabric constructed according to the present invention. The landing area plane can be defined by a warp knuckle, a shute knuckle, or by both. The landing area plane is the z-direction plane intersecting the top of the elements forming a landing area disposed on the web contacting surface of the fabric.
As used herein the term “discrete” when referring to a protuberance of a papermaking fabric according to the present invention means that the protuberance is visually unconnected from other protuberances and does not extend continuously in any dimension of the papermaking fabric surface. A protuberance may be discrete despite being formed from a single continuous filament. For example, a single continuous warp filament may be woven such that it forms a plurality of discrete substantially machine direction oriented protuberances where each protuberance has a first proximal end and a first distal end where the ends of the protuberance terminate at spaced apart shute filaments.
As used herein the term “continuous” when referring to a three-dimensional element of a papermaking fabric according to the present invention, such as protuberance or a pattern, means that the element extends throughout one dimension of the papermaking fabric surface. When referring to a protuberance the term refers to a protuberance comprising two or more warp filaments that extend without interruption throughout one dimension of the woven fabric.
As used herein, the term “uninterrupted” generally refers to a protuberance having an upper surface plane that extends without interruptions and remains above the landing area surface plane for length of the protuberance. Undulations of the upper surface plane within a protuberance along its length such as those resulting from twisting of warp filaments or warp filaments forming the protuberance tucking under one another are not considered to be interruptions.
As used herein the term “substantially machine direction oriented” as it refers to a protuberance means that the total length of the protuberance that is positioned at an angle of greater than 45 degrees to the cross-machine direction is greater than the total length of the protuberance that is positioned at an angle of 45 degrees or less to the cross-machine direction.
As used herein the term “pattern” refers to any non-random repeating design, figure, or motif. Generally the fabrics of the present invention may comprise decorative patterns comprising a plurality of line elements, however, it is not necessary that the line elements form recognizable shapes, and a repeating design of the line elements is considered to constitute a decorative pattern.
As used herein the term “twill pattern” generally refers to a pattern of parallel protuberances having an element angle greater than about 0.5 degrees, such as from about 0.5 to about 20 degrees, and protuberances that extend uninterrupted along their entire distance. In a particularly preferred embodiment all of the parallel protuberances forming a twill pattern are equally spaced from one another to provide the pattern with a pitch greater than about 0.5 mm, such as from about 0.5 to about 5.0 mm.
The present inventors have now surprisingly discovered that certain papermaking belts having high topography, or textures, disposed thereon may be used to produce tissue webs and products that are both smooth and have high bulk with improved operating efficiency. Accordingly, in certain embodiments the present invention provides an apparatus for manufacturing paper and more preferably tissue webs and products. The apparatus according to the present invention is preferably embodied in a papermaking fabric. In preferred embodiments, the papermaking fabric can be utilized as a transfer fabric. As used herein, “papermaking belt” may be synonymous with “papermaking fabric.”
With reference now to
The web contacting side 20 of the fabric 10 comprises a plurality of protuberances 22. The protuberances 22 are generally disposed on the web-contacting surface 20 for cooperating with, and structuring of, the wet fibrous web during manufacturing. In a particularly preferred embodiment the web contacting surface 20 comprises a plurality of spaced apart three dimensional protuberances 22 distributed across the web-contacting surface 20 of the fabric 10 and together constituting from at least about 15 percent of the web-contacting surface, such as from about 15 to about 35 percent, more preferably from about 18 to about 30 percent, and still more preferably from about 20 to about 25 percent of the web-contacting surface.
The protuberances 22, such as those illustrated in
Generally the protuberances are spaced apart from one another so as to define landing areas there-between. In certain instances, such as when the instant papermaking fabrics are used as a through-air drying fabric, the fibers of the embryonic tissue web are deflected in the z-direction by the protuberances, which bound landing areas, and are disposed along the landing area plane to yield a web having a three-dimensional topography. The spacing of protuberances can be provided such that the tissue web conforms to the protuberances and is deposited in the landing area without tearing.
With continued reference to
With reference now to
As will be discussed in more detail below, it is generally preferred that at least a portion of the protuberances are permeable to liquids and allow water to be removed from the cellulosic fibrous structure by the application of differential fluid pressure, by evaporative mechanisms, or both when drying air passes through the embryonic tissue web while on the papermaking fabric or a vacuum is applied through the papermaking fabric. Accordingly, it is generally preferred that at least a portion of the protuberances be hollow.
With continued reference to
The plurality of protuberances and landing areas provide a textured surface for contacting the web. In some embodiments, the plurality of protuberances and landing areas can provide a decorative pattern on the papermaking fabric. For example, it is contemplated that a protuberance could be linear, arcuate, or sinusoidal in shape, or any other suitable shape. The protuberances can form shapes such as rectangles, squares, circles, ovals, etc. The protuberances can form an array of rows and/or columns, and in some embodiments, can be evenly spaced in either or both the machine direction and the cross-machine direction. In the embodiment illustrated in
Generally at least one protuberance 22 is hollow and includes an internal pocket 26 (delineated by dashed line 29 in
The shape of the hollow interior pocket may be, for example, semi-circular, round, oval, or rectangular. In one preferred embodiment, the hollow interior pocket may be somewhat domed and have non-linear top edges when viewed in the cross-section. Both the width and height of the hollow internal pockets can be varied. Further, the size of the internal pocket may vary within a particular or individual protuberance and it also may vary as between different protuberance. With reference to
One advantage of providing at least a portion of the protuberances with a hollow interior pocket is that the pocket may facilitate air transfer throughout the internal pocket in the plane of the machine direction and the cross-machine direction, and additionally, through the papermaking fabric on both the machine contacting side and the web contacting side due to the interstitial spacing between the filaments defining the internal pocket. In this manner a fabric may be provided in which both the protuberances and the landing areas are air permeable and more preferably both are permeable to both air and water. Making both the protuberances and the landing areas air permeable increases the overall permeability of the fabric and can provide a distinct advantage over woven papermaking fabrics that include filaments that are stacked to form the protuberances and are not air permeable. Compared to prior art woven fabrics, the instant woven fabrics may have increased air permeability from the web to machine contacting sides of the fabric and the permeability may be more uniform throughout the web contacting surface of the fabric. Further, the improvement in permeability is achieved without a loss in web contacting surface topography. The present fabrics may produce tissue products having improved properties, while also providing enhanced drying and handling characteristics for a tissue web being transported by and/or manufactured on the papermaking fabric.
Additionally, an air permeability of the machine contacting side of the papermaking fabric can be substantially the same as an air permeability of the web contacting side of the papermaking fabric. For purposes herein, the air permeability can be measured by the Frazier Air Permeability test as known in the art. The Frazier Air Permeability test measures the permeability of a fabric as standard cubic feet of air flow per square foot of material per minute with an air pressure differential of 0.5 inches (12.7 mm) of water under standard conditions. For example, throughdrying fabrics can have a permeability from about 55 standard cubic feet per square foot per minute (about 16 standard cubic meters per square meter per minute) or higher, more specifically from about 100 standard cubic feet per square foot per minute (about 30 standard cubic meters per square meter per minute) to about 1,700 standard cubic feet per square foot per minute (about 520 standard cubic meters per square meter per minute), and most specifically from about 200 standard cubic feet per square foot per minute (about 60 standard cubic meters per square meter per minute) to about 1,500 standard cubic feet per square foot per minute (about 460 standard cubic meters per square meter per minute). For purposes herein, two measured air permeabilities can be referred to as being “substantially the same” when one air permeability value is within 5 percent of the comparative air permeability value.
In embodiments where the papermaking fabric is utilized as a transfer fabric, the papermaking fabric can provide improved dewatering of the tissue web before the sheet is delivered to the through-air drying fabric. It is believed that the papermaking fabric can provide improve sheet uniformity and lead to a reduction in pin holes. This can provide benefits in drying at the through-air drying fabric as well as with improved properties (e.g., tensile strength) of the tissue web.
In the embodiments illustrated in
The cross-section shape of the protuberance may vary depending on the size, shape and number of warp filaments that make-up the protuberance. For example, as illustrated in
In certain embodiments it may be preferred that for a given protuberance the upper surface plane extends uninterrupted for the length of the protuberance resulting in a protuberance having a height that is generally uniform along its length. For example, where a protuberance is continuous and extends throughout one dimension of the papermaking fabric its upper surface plane is preferably uninterrupted along the entire length to provide a single protuberance a substantially continuous height along its length. While it is generally desirable that the height of a protuberance be substantially constant along its length slight height variances can be expected as a result of the protuberances being formed from woven filaments. For example, it may be desirable that the height of a given protuberance vary less than ±150 μm and more preferably less than about ±100 μm along its length. To ensure that the height of a given protuberance is substantially constant along its length, it may be preferable to weave the protuberances from one or more warp filaments without inspecting or interrupting the one or more warp filaments with shute filaments.
The protuberance width (w) may also vary depending on the construction of the fabric and its intended use. Protuberance width (w) is generally measured normal to the principal dimension of the protuberance in a plane defined by the cross-machine direction (CD) at a given location. Where the protuberance has a generally square or rectangular cross-section, the width is generally measured as the distance between the two planar sidewalls that form the protuberance. In those cases where the protuberance does not have planar sidewalls the width is measured at the point that provides the greatest width for the configuration of the protuberance. For example, the width of a protuberance not having two planar sidewalls may be measured along the base of the protuberance. In some preferred embodiments, the width of the protuberances can be from about 0.20 to about 3.00, or preferably from about 0.50 to about 2.50 mm, or even more preferably from about 0.70 to about 1.50 mm. Of course, it is contemplated that the width can be outside of the preferred range in some embodiments and still be within the scope of this disclosure.
In certain embodiments the protuberances do not have planar sidewalls, but rather have a generally semi-circular cross-sectional shape. In other embodiments however, the protuberance may be woven so as to form a pair of opposed sidewalls and provide the protuberance with a rectilinear cross-section shape. For example, in one embodiment the protuberance may have a square cross-sectional shape, where the width and height are substantially equal and vary from about 0.5 and 3.5 mm, more preferably from about 0.5 to about 1.5 mm, and in a particularly preferred embodiment between from about 0.7 to about 1.0 mm. However, it is to be understood that because the protuberance are formed from woven filaments having generally circular or oval cross-sectional shapes, the cross-sectional shape of the resulting protuberance may not be perfectly rectilinear, but may have some other cross-sectional shape that is approximately rectilinear.
The spacing and arrangement of protuberances may vary depending on the desired tissue product properties and appearance. If the individual protuberances are too high, or the valley area is too small, the resulting sheet may have excessive pinholes and insufficient compression resistance, CD stretch, and CD TEA, and be of poor quality. Further, tensile strength may be degraded if the span between protuberances greatly exceeds the fiber length. Conversely, if the spacing between adjacent protuberances is too small the tissue will not mold into the valleys without rupturing the sheet, causing excessive sheet holes, poor strength, and poor paper quality.
In one embodiment a plurality of protuberances extends continuously throughout one dimension of the fabric and each protuberance in the plurality is spaced apart from the adjacent protuberance. Thus, the protuberances may be spaced apart across the entire cross-machine direction of the fabric or may run diagonally relative to the machine and cross-machine directions. Of course, the directions of the protuberances alignments (machine direction, cross-machine direction, or diagonal) discussed above refer to the principal alignment of the protuberances. Within each alignment, the protuberances may have segments aligned at other directions, but aggregate to yield the particular alignment of the entire protuberance.
Further while the illustrated fabrics, such as those shown in
In addition to varying the spacing and arrangement of the protuberances along the fabric, the shape of the protuberance may also be varied. For example, in one embodiment, the protuberances are arranged substantially parallel to one another such that none of the protuberances intersect one another. For example, each of the protuberances may be arranged generally parallel to one another, with no two protuberances crossing one another and each of the protuberances equally spaced apart from one another. Generally, the center-to-center spacing of individual protuberances (also referred to herein as pitch or simply as P) may be greater than about 1.0 mm, such as from about 1.0 to about 20.0 mm apart and more preferably from about 2.0 to about 10.0 mm apart. In one particularly preferred embodiment the protuberances are spaced apart from one-another from about 3.8 to about 4.4 mm. This spacing will result in a tissue web which generates maximum caliper when made of conventional cellulosic fibers. Further, this arrangement provides a tissue web having three dimensional surface topography, yet relatively uniform density.
In a particularly preferred embodiment, such as that illustrated in
Exemplary weave patterns and methods of manufacturing a woven papermaking fabric will now be described. In one embodiment, the papermaking fabric could be manufactured by providing a first set of filaments and a second set of filaments that are woven in a weave pattern where the first set of filaments has a different shrinkage property than the second set of filaments. Upon heat finishing the woven papermaking fabric, the difference in shrinkage properties between the first set of filaments and the second set of filaments causes buckling of the woven papermaking fabric to provide protuberances with hollow internal pockets, as discussed above.
In the weave pattern 30 depicted in the unit cell of
The difference in shrinkage properties between filaments 12 of the weave pattern 30 discussed above can be provided in different ways. For example, the first shute filaments 16a having a first shrinkage property and the second shute filaments 16b having a second shrinkage property can be provided such that the first shute filaments 16a could be comprised of a different material than the second shute filaments 16b that have different shrinkage characteristics from one another. Alternatively and/or additionally, the first shute filaments 16a and the second shute filaments 16b could comprise the same material, such as polyethylene teraphthalate (PET), but the first shute filaments 16a could be processed in a different manner than the second shute filaments 16b such that the first shute filaments 16a have a different shrinkage property than the second shute filaments 16b. As but one example, the first shute filaments 16a could be DFP 347 (PET) and the second shute filaments 16b could be DFP 533 (PET), with the DFP 347 filaments having a higher free shrink than the DFP 533 filaments.
In one embodiment, the warp filaments 14 can have the same or a similar shrinkage property to the second shute filaments 16b having the second shrinkage property. In some embodiments, the warp filaments 14 can comprise a third shrinkage property that can be different than the first shrinkage property and/or the second shrinkage property. It is also conceived that the shute filaments 16 could include various other filaments that have different shrinkage properties than the first shrinkage property of the first shute filaments 16a and the second shrinkage property of the second shute filaments 16b. Similarly, it is also conceived that the warp filaments 14 could include filaments that have more than two different shrinkage properties. One exemplary warp filament 14 that can be preferred for a papermaking fabric 10 used as a transfer fabric can include FFP 875 (PET). One exemplary warp filament 14 that can be preferred for a papermaking fabric 10 used as a through-air drying fabric can be FFA 915 (Polyphenylene sulphide or PPS).
The weave pattern 30 of
The weave pattern 30 of
After the weave pattern 30 of
It is to be understood that other weave patterns can also be utilized by one of ordinary skill in the art to provide a papermaking fabric 10 with at least one protuberance 22 with a hollow internal pocket 26. The use of at least two sets of filaments having different shrinkage properties, but variances in the weave pattern 30 from that as described above, can provide different patterns of protuberances 22 with internal pockets 26 to provide different decorative patterns as desired. For example, while the weave patterns 30, 130 provide protuberances 22 oriented in a twill pattern and in a machine-direction oriented pattern, respectively, it is contemplated that alternative weave patterns could be constructed to provide CD oriented protuberances 22 including internal pockets 26. For instance, a weave pattern could include warp filaments 14 having different sets of filaments with different shrinkage properties from one another (such as a set of DFP 347 filaments and a set of DFP 533 filaments), such that the shrinkage and buckling occurs in the machine direction to form CD oriented protuberances 22 having internal pockets 26. It is to be appreciated that other weave patterns could provide a plurality of protuberances 22 with internal pockets 26 in which some of the protuberances 22 extend in the machine direction and some of the protuberances 22 extend in the cross-machine direction. It is also contemplated that weave patterns could be modified to provide protuberances 22 that form various other decorative patterns on a papermaking fabric 10.
Additionally, the papermaking fabric 10 can include additional components as is known in the art, such as sacrificial wear elements (not shown). The sacrificial wear elements can be disposed on the machine contacting side 18 of the papermaking fabric 10 and can be of a variety of shapes and sizes, such as rounded, rectangular, sinusoidal, etc. The sacrificial wear elements can extend the effective life of the papermaking fabric 10.
Profilometry scans of the fabric contacting surface of a sample were created using an FRT MicroSpy® Profile profilometer (FRT of America, LLC, San Jose, Calif.) and then analyzing the image using Nanovea® Ultra software version 7.4 (Nanovea Inc., Irvine, Calif.). Samples were cut into squares measuring 145×145 mm. The samples were then secured to the x-y stage of the profilometer using an aluminum plate having a machined center hole measuring 2×2 inches, with the fabric contacting surface of the sample facing upwards, being sure that the samples were laid flat on the stage and not distorted within the profilometer field of view.
Once the sample was secured to the stage the profilometer was used to generate a three dimension height map of the sample surface. A 1602×1602 array of height values were obtained with a 30 μiη spacing resulting in a 48 mm MD×48 mm CD field of view having a vertical resolution 100 nm and a lateral resolution 6 um. The resulting height map was exported to .sdf (surface data file) format.
Individual sample .sdf files were analyzed using Nanovea® Ultra version 7.4 by performing the following functions:
(1) Using the “Thresholding” function of the Nanovea® Ultra software the raw image (also referred to as the field) is subjected to thresholding by setting the material ratio values at 0.5 to 99.5 percent such that thresholding truncates the measured heights to between the 0.5 percentile height and the 99.5 percentile height; and
(2) Using the “Fill In Non-Measured Points” function of the Nanovea® Ultra software the non-measured points are filled by a smooth shape calculated from neighboring points.
Embodiment 1: A woven papermaking fabric having a machine direction (MD) axis and cross-machine direction (CD) axis, a machine contacting side and a web contacting side, the fabric comprising a plurality of substantially MD oriented warp filaments, and a plurality of substantially CD oriented shute filaments, the shute filaments being interwoven with warp filaments to provide at least one protuberance on the web contacting side of the fabric, the at least one protuberance having a hollow internal pocket.
Embodiment 2: The papermaking fabric of embodiment 1, wherein the at least one protuberance is air permeable.
Embodiment 3: The papermaking fabric of embodiments 1 or 2, wherein the plurality of filaments comprise: a first set of filaments having a first shrinkage property; and a second set of filaments having a second shrinkage property, the first shrinkage property being different from the second shrinkage property, wherein the difference between the first shrinkage property and the second shrinkage property creates the at least one protuberance upon heat finishing of the first set of filaments and the second set of filaments.
Embodiment 4: The papermaking fabric of embodiment 3, wherein the first set of filaments and the second set of filaments are shute filaments.
Embodiment 5: The papermaking fabric of embodiment 3 or embodiment 4, wherein the difference between the first shrinkage property and the second shrinkage property is provided by the first set of filaments comprising a first material and the second set of filaments comprising a second material, the first material being different from the second material.
Embodiment 6: The papermaking fabric of embodiment 3 or embodiment 4, wherein the difference between the first shrinkage property and the second shrinkage property is provided by the first set of filaments comprising a first processing parameter and the second set of filaments comprising a second processing parameter, the first processing parameter being different from the second processing parameter.
Embodiment 7: The papermaking fabric of any of the preceding embodiments, further comprising a plurality of protuberances on the web contacting side of the papermaking fabric, the plurality of protuberances providing a plurality of internal pockets, and the plurality of protuberances being air permeable.
Embodiment 8: The papermaking fabric of embodiment 7, wherein the plurality of protuberances are continuous.
Embodiment 9: The papermaking fabric of embodiment 7, wherein the plurality of protuberances are discontinuous.
Embodiment 10: A papermaking fabric including a machine contacting side and a web contacting side, the papermaking fabric comprising: a first set of filaments including a first shrinkage property; and a second set of filaments including a second shrinkage property, the first shrinkage property being different from the second shrinkage property; the first set of filaments and the second set of filaments being woven and providing at least one protuberance on the web contacting side of the papermaking fabric, the at least one protuberance defining a hollow internal pocket.
Embodiment 11: The papermaking fabric of embodiment 10, wherein the at least one protuberance is air permeable.
Embodiment 12: The papermaking fabric of embodiment 10 or 11, wherein the internal pocket is continuous for the length of the papermaking fabric.
Embodiment 13: The papermaking fabric of embodiment 10, further comprising a plurality of protuberances on the web contacting side including a hollow internal pocket, the plurality of protuberances being air permeable.
Embodiment 14: The papermaking fabric of any one of embodiments 10 through 13, wherein the difference between the first shrinkage property and the second shrinkage property is provided by the first set of filaments comprising a first material and the second set of filaments comprising a second material, the first material being different from the second material.
Embodiment 15: The papermaking fabric of any one of embodiments 10 through 13, wherein the difference between the first shrinkage property and the second shrinkage property is provided by the first set of filaments comprising a first processing parameter and the second set of filaments comprising a second processing parameter, the first processing parameter being different from the second processing parameter.
Embodiment 16: A method of manufacturing a papermaking fabric, the method comprising: providing a plurality of warp filaments and a plurality of shute filaments for weaving, at least one of the plurality of warp filaments and the plurality of shute filaments comprising: a first set of filaments including a first shrinkage property; and a second set of filaments including a second shrinkage property, the first shrinkage property being different than the second shrinkage property; weaving the shute filaments and the warp filaments in a weave pattern to provide a woven fabric including a first machine direction end opposite from a second machine direction end and a machine contacting side opposite from a web contacting side; heat finishing the first set of filaments and the second set of filaments after the plurality of shute filaments and the plurality of warp filaments are woven, the weave pattern and the heat finishing providing at least one protuberance including a hollow internal pocket, the internal pocket including a height and a width; and connecting the first machine direction end of the woven fabric to the second machine direction end of the woven fabric to provide a seam for the papermaking fabric.
Embodiment 17: The method of embodiment 16, wherein the protuberance is air permeable.
Embodiment 18: The method of embodiment 16 or 17, wherein the weave pattern comprises a plurality of floats and at least one high friction tying area, wherein each of the floats of the plurality of floats are spaced apart from one another, and the high friction tying area is located between spaced floats.
Embodiment 19: The method of any one of embodiments 16 through 18, wherein the first set of filaments and the second set of filaments each serve as shute filaments in the loom.
Embodiment 20: The method of any one of embodiments 16 through 19, wherein the weave pattern and the heat finishing provide a plurality of protuberances including a hollow internal pocket, the plurality of protuberances being air permeable.
While the invention has been described in detail with respect to the specific embodiments thereof, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing, may readily conceive of alterations to, variations of, and equivalents to these embodiments. Accordingly, the scope of the present disclosure should be assessed as that of the appended claims and any equivalents thereto.
Filing Document | Filing Date | Country | Kind |
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PCT/US17/67176 | 12/19/2017 | WO | 00 |
Number | Date | Country | |
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62440585 | Dec 2016 | US |