Apertured papermaking press felts and resulting paper products

Abstract

Apertured press felts for use in conventional wet-press (CWP) papermaking machines, methods of making paper products using the apertured press felts, and single or multi-ply paper products made therefrom.

Description

Attorney Docket No.: GP-23037-WO-PCT APERTURED PAPERMAKING PRESS FELTS AND RESULTING PAPER PRODUCTS TECHNICAL FIELD

[0001] The present application discloses apertured papermaking press felts comprising a plurality of pores (apertures) extending into the interior of the press felt. The felt, pores, and pore pattern can be characterized by one or more physical attributes set out herein. The present application further discloses methods of making a paper sheet on a conventional wet-press papermaking machine with a press felt as described above and paper products resulting therefrom. BACKGROUND

[0002] Wet press felts are known to be useful in the process of manufacturing paper products, such as tissue and towel products. Paper products are conventionally manufactured by conveying an aqueous slurry of cellulosic fibers on a moving wire, fabric, or felt along a papermaking machine. As the aqueous slurry is conveyed, water is drained and an embryonic cellulosic web begins to form.

[0003] Press felts may be used in the press section of the papermaking machine to facilitate withdrawal of additional water from the embryonic cellulosic web following formation. This process is also called press dewatering. The dewatering process typically involves transporting the cellulosic web through a nip or series of nips, along with one or more press felts, to apply pressure in the nip which facilitates removal of water from the cellulosic web and transfer of that water to and out of the press felt. This dewatering process causes the fibers in the cellulosic web to further adhere to one another and to form a cellulosic sheet for further processing in the dryer and other sections of the papermaking machine. It is, therefore, desirable that the press felt be able to accept the water extracted from the wet cellulosic web in the press section. Relatedly, the press felt should be able to prevent the removed water from returning to the cellulosic web. The press felt must also be able to support and carry the cellulosic web through the dewatering process.

[0004] There are a variety of press felt designs used in the art, and a particular press felt may be chosen based on its ability to impart desirable properties to the cellulosic sheet being manufactured. Traditional press felt designs comprise a single, unified woven base core material with a sheet-side fibrous batting material attached thereto. As used herein, the term sheet-sideAttorney Docket No.: GP-23037-WO-PCT refers to the side of the press felt that is adjacent to the cellulosic web during dewatering. Conversely, the term roll-side refers to the side of the press felt that is adjacent to the press roll during dewatering. In some traditional press felt designs, the base core material may be surrounded by fibrous batting on both the sheet-side and the roll-side of the press felt.

[0005] Different press felt designs have been studied with the goal of increasing the caliper or bulk of the resulting cellulosic sheet. Unfortunately, prior press felt designs were either unable to increase caliper or bulk, or the ones that did were found to come at the expense of other properties, such as sheet strength, absorbency, and / or softness. In other words, caliper improvements are commonly achieved at the expense of softness and vice versa.

[0006] There is thus a need for a method of making a cellulosic sheet using a press felt design on a conventional wet press machine capable of effectively and efficiently drying and producing a sheet with at least one of increased caliper, bulk, and / or absorbency, but without concomitant losses in sheet strength or softness.

[0007] This need has been met by the press felts according to the present disclosure, which are capable of producing increases in one or more of caliper, bulk, absorbency, and / or softness, among other benefits. SUMMARY

[0008] The disclosed embodiments herein provide press felts for use in a conventional wet-press papermaking machine, wherein the press felt comprises a sheet-side surface and a roll-side surface; wherein the sheet-side surface comprises a plurality of pores extending into the interior of the press felt towards the roll-side surface. The felt and pores can be characterized by one or more physical attributes set out herein.

[0009] Further disclosed herein are methods of making a paper sheet on a conventional wet- press papermaking machine comprising: dewatering a cellulosic web in the press section of a conventional wet-press papermaking machine with a press felt to form a paper sheet, wherein the press felt comprises: a sheet-side surface and a roll-side surface; wherein the sheet-side surface comprises a plurality of pores extending into the interior of the press felt towards the roll-side surface; wherein the felt and pores can be characterized by one or more physical attributes as set out herein.Attorney Docket No.: GP-23037-WO-PCT

[0010] Further disclosed herein are paper products made by a process comprising: dewatering a cellulosic web in the press section of a conventional wet-press papermaking machine with a press felt to form a paper sheet, wherein the press felt comprises: a sheet-side surface and a roll- side surface; wherein the sheet-side surface comprises a plurality of pores extending into the interior of the press felt towards the roll-side surface; wherein the felt and pores can be characterized by one or more physical attributes as set out herein; and converting the paper sheet into a paper product. The resultant paper products are thick, soft, and absorbent. BRIEF DESCRIPTION OF THE FIGURES

[0011] FIGURE 1 is a schematic diagram of an exemplary conventional wet-press (CWP) papermaking machine with a crescent forming section having a suction turning roll.

[0012] FIGURE 2 is a schematic diagram of an exemplary CWP papermaking machine with a crescent forming section having a suction turning roll and a shoe press nip.

[0013] FIGURE 3 is a schematic diagram of an exemplary shoe press nip in a CWP papermaking machine.

[0014] FIGURE 4 depicts an exemplary press felt with a pore pattern according to some embodiments of the present disclosure, as viewed from above the sheet-side surface of the felt.

[0015] FIGURE 5 depicts a close up of a sample of the pore pattern depicted in the press felt of FIG.4.

[0016] FIGURE 6 depicts a cross-sectional view of a press felt according to some embodiments of the present disclosure.

[0017] FIGURE 7 is a scanning electron microscope (SEM) image of a cross-section of an exemplary press felt with a pore pattern according to some embodiments of the present disclosure.

[0018] FIGURE 8 depicts a close up of a sample of a press felt with a pore pattern according to some embodiments of the present disclosure, as viewed from above the sheet-side surface of the felt, showing the pore area within the circles and the contact area outside the circles.

[0019] FIGURE 9 depicts a close up of a sample of press felt with a pore pattern according to some embodiments of the present disclosure, as viewed from above the sheet-side surface of theAttorney Docket No.: GP-23037-WO-PCT felt, showing fused areas surrounding the individual pores in black and the remaining, non-fused contact area in grey.

[0020] FIGURE 10 depicts an exemplary press felt with a pore pattern having a pattern offset in the machine direction according to some embodiments of the present disclosure, as viewed from above the sheet-side surface of the felt.

[0021] FIGURE 11 is an image of an exemplary press felt with a pore pattern according to some embodiments of the present disclosure, as viewed from above the sheet-side surface of the felt, exhibiting a contact area of about 60%.

[0022] FIGURE 12 is an image of an exemplary press felt with a pore pattern according to some embodiments of the present disclosure, as viewed from above the sheet-side surface of the felt, exhibiting a contact area of about 75%.

[0023] FIGURE 13 is an image of a comparative press felt according to FIG.7 of U.S. Pat. No. 11,098,450 B2, as viewed from above the sheet-side surface of the felt, exhibiting a relatively low contact area and an almost entirely fused contact area.

[0024] FIGURE 14 depicts a cross-sectional view of an interaction between an exemplary press felt according to some embodiments of the present disclosure and a cellulosic web during pressing.

[0025] FIGURE 15 depicts a cross-sectional view of a paper sheet resulting from the pressing of a cellulosic web with a press felt according to FIG.14.

[0026] FIGURE 16 is an image of the felt-side (also known as the air-side) surface of a comparative paper sheet formed with a conventional press felt lacking pores as required of the present disclosure.

[0027] FIGURE 17 is an image of the felt-side (also known as the air-side) surface of an exemplary a paper sheet formed with a press felt according to the present disclosure, exhibiting domes corresponding to the pores in the press felt.

[0028] FIGURE 18 is an image of the Yankee-side surface of an exemplary paper sheet formed with a press felt according to the present disclosure, exhibiting negative protrusions corresponding to the pores in the press felt.Attorney Docket No.: GP-23037-WO-PCT

[0029] FIGURES 19A and 19B are microtomography (Micro-CT) images of paper sheets, showing the relative density of the sheets across their surface. FIG.19A is a density map of a comparative paper sheet formed with a press felt as shown in FIG.7 of U.S. Pat. No.11,098,450 B2. FIG.19B is a density map of exemplary a paper sheet formed with a press felt according to the present disclosure.

[0030] FIGURES 20A, 20B, and 20C are X-Ray images of paper sheet cross-sections. FIG.20A is a cross-section of a comparative paper sheet formed with a conventional, non-apertured press felt. FIG.20B is a cross-section of a comparative paper sheet formed with a press felt as shown in FIG.7 of U.S. Pat. No.11,098,450 B2. FIG.20C is a cross-section of an exemplary paper sheet formed with a press felt according to the present disclosure.

[0031] FIGURE 21 is an SEM image of a cross-section of an exemplary paper sheet formed with a press felt according to the present disclosure, exhibiting domes corresponding to the pores in the press felt. The domes of the paper sheet lack crepe bars, while the sections of the paper sheet between domes exhibit crepe bars. DETAILED DESCRIPTION

[0032] Paper products may be made using conventional wet-press (CWP) processes and apparatus. In accordance with the present disclosure, any CWP papermaking machine may be used. As shown in FIG.1, an exemplary CWP papermaking machine 10 may be a two-fabric loop machine having a forming section 32 (generally referred to in the art as a crescent former), a felt run 34, a press section 36, and a drying section 38. The forming section 32 includes a forming wire 122 supported by a plurality of rolls such as rolls 132 and 135. The forming section 32 also includes a forming roll 58 which supports a press felt 1. A headbox 60 provides papermaking furnish at the forming roll 58 to form a nascent web 64 on press felt 1. The web is of low consistency as it is initially transferred to the press felt.

[0033] Once formed, the web 64 advances on the press felt 1 in the machine-direction indicated by arrow 86 through felt run 34. Direction 86 is referred to as the machine direction (MD) of the web as well as that of CWP papermaking machine 10; whereas the cross-machine direction (CD) is the direction in the plane of the web perpendicular to the MD. The felt run 34 includes a plurality of rolls such as rolls 142 and 145 which further support the press felt 1.Attorney Docket No.: GP-23037-WO-PCT

[0034] The felt run 34 extends to a press section 36 defined by a press roll 66. As the web reaches the press section 36, it may have a consistency of 10 to 25 percent or so. In the press section 36, the web 64 enters nip 78 between press roll 66 and Yankee cylinder 100. The web 64 is wet-pressed on the press felt 1 in nip 78 and is thus compactivity dewatered, typically increasing the consistency by 15 or more points at this stage of the process.

[0035] As used herein, the terms “web,” “cellulosic web,” “fibrous web,” “paper web,” and “paper sheet” are used interchangeably to refer to the cellulosic web that is dewatered in the press section of a papermaking machine using a press felt as disclosed herein. In some instances, it is referred to as a “web,” “cellulosic web” or “fibrous web” before wet pressing and as a “paper web” or “paper sheet” after wet pressing, but the terms may be used interchangeably.

[0036] As it leaves the press nip 78, the paper web 64 is transferred onto Yankee cylinder 100, optionally with the use of an adhesive to adhere the web onto the Yankee surface. The dewatered paper web 64 is then dried on Yankee cylinder 100, which is a heated cylinder, and by a high jet velocity impingement air in Yankee hood 108. As the cylinder rotates, paper web 64 is creped from the cylinder by creping (doctor) blade 109 and wound on a take-up reel 110.

[0037] There is optionally provided a calender station 40 with rolls 40(a) and 40(b) to calender the sheet, if so desired.

[0038] In an alternative embodiment and as exemplified in FIG.2, a CWP papermaking machine 20 with a crescent forming section may utilize both a suction roll 74 and a shoe press 68 in the press section 36. The shoe press roll construction is pictured close-up in FIG.3. In operation, press felt 1 conveys web 64 around a suction roll 74 into a press nip 78. In nip 78, the web 64 is compactively dewatered on the press felt 1 with the assistance of a pressure shoe 82 and transferred to a transfer the Yankee cylinder 100.

[0039] As it relates to the present application, the press felts may participate in the finishing of the surface of the cellulosic sheet, creating a textured surface. For example, when a cellulosic web is contacted by the press felt, portions of the web contact the flat, contact surface and other portions of the web are drawn into the apertures. Before being removed from the felt, the web is dewatered such that its shape is partially fixed or locked. Domes are thereby formed where the web was drawn into the apertures of the felt, and those domes are present in the finished paperAttorney Docket No.: GP-23037-WO-PCT sheet. Hence, the paper product has a distinct three-dimensional structure formed, in part, by the apertured surface characteristics of the press felt.

[0040] The present description discloses press felts for use in a conventional wet-press papermaking machine wherein the press felt comprises a sheet-side surface and a roll-side surface and wherein the sheet-side surface comprises a plurality of pores (apertures) extending into the interior of the press felt towards the roll-side surface. When viewed from above the sheet-side surface, the plurality of pores creates a pore pattern across the sheet-side surface, extending in the MD and CD directions.

[0041] Without wishing to be bound by theory, the pore geometries as described herein (e.g., shape, depth, diameter, 90% depth diameter, side-wall angle, etc.) allow the pore cavities to be sufficiently accessible by the fibers in the paper sheet during pressing to allow for efficient and effective dewatering of the paper web and the creation of the resulting dome structures on the paper sheet. Thus, the hole geometries as described herein, in combination the pore pattern geometries described herein (e.g., pore area, contact area, pore pattern MD and CD distance, pore density, pattern offset angle, etc.) are believed to result in improved properties of the paper product, including one or more of improved caliper / bulk, absorbency, and / or softness.

[0042] FIG.4 depicts an exemplary press felt 1 comprising a sheet-side surface 3 with a plurality of pores 2 extending into the interior of the press felt towards the roll-side surface. As viewed from above the sheet-side surface 3, the plurality of pores 2 creates a pore pattern across the sheet-side surface 3, extending in the MD direction and CD direction.

[0043] Any art-recognized press felt structure can be used with the apertured surface of the present disclosure. For example, the press felts can include a woven base core material with a sheet-side fibrous batting material attached thereto. As another example, the press felts can include a woven base core material surrounded by fibrous batting on both the sheet-side and the roll-side of the press felt. The woven base core material may comprise any conventional material used as the base core, such as a yarn extruded from one or more synthetic polymeric resins (such as polyamide and polyester resins), which may be monofilament or multifilament, and in either a single-layer, multi-layered or laminated configuration, such as in a double-layer base weave, a triple-layer base weave, a laminated base weave, or any suitable weave pattern. The batting material may comprise any conventional material used as batting, for example a fine,Attorney Docket No.: GP-23037-WO-PCT non-woven fibrous material, such as nylon, wool, and the like, which may be needled into the base core material. The fibrous batting material may be either the same throughout the press felt or varied, for example different on the roll side versus the sheet side, or in layers comprising different types of fibers throughout the thickness.

[0044] The pores have a sheet-side surface shape defined by the opening of the individual pores in the pore pattern as viewed from above the sheet-side surface of the felt. In some embodiments, the sheet-side surface pore shape is irregular. In some embodiments, the sheet- side surface pore shape is substantially geometric. In some embodiments, the sheet-side surface pore shape is chosen from circular and oval. In some embodiments, the sheet-side surface pore shape is substantially circular. In some embodiments, the pores are discrete and non- overlapping.

[0045] The pores have a cross-sectional shape defined by the outline of the individual pores in the pore pattern as viewed from a cross-section of the felt through the center of the pore at the pore depth. In some embodiments, the cross-sectional pore shape is irregular. In some embodiments, the cross-sectional pore shape is substantially conical. In some embodiments, the cross-sectional pore shape is substantially conical until transitioning to a substantially round bottom at the pore depth (see FIG.7).

[0046] In some embodiments, the pores have a surface diameter defined as the average diameter at the sheet-side surface of the individual pores in the pore pattern. For pore shapes that are non- circular, pore surface diameter may be determined by averaging the average pore width and the average pore length. In some embodiments, the pore surface diameter is from about 0.5 mm to about 3.0 mm. The pore surface diameter can vary depending on the type of paper product being formed and desired attributes of that resulting product.

[0047] In some embodiments, the pore surface diameter is from about 0.5 to 1.8 mm. In some embodiments, the pore surface diameter is from about 1.0 mm to about 1.5 mm. In some embodiments, the pore surface diameter is from about 1.1 mm to about 1.3 mm. In some embodiments, the pore surface diameter is from about 1.15 mm to about 1.25 mm. In some embodiments, the pore surface diameter is about 1.2 mm. In some embodiments, the pore surface diameter is from about 1.3 mm to about 1.5 mm. In some embodiments, the pore surface diameter is from about 1.35 mm to about 1.45 mm. In some embodiments, the pore surfaceAttorney Docket No.: GP-23037-WO-PCT diameter is about 1.4 mm. In some embodiments, the pore surface diameter is from about 1.5 mm to about 2.0 mm. In some embodiments, the pore surface diameter is from about 1.7 mm to about 1.9 mm. In some embodiments, the pore surface diameter is from about 1.75 mm to about 1.85 mm. In some embodiments, the pore surface diameter is about 1.8 mm. In some embodiments, the pore surface diameter is from 1.8 mm to about 3.0 mm. In some embodiments, the pore surface diameter is from about 2.0 mm to about 2.5 mm. In some embodiments, the pore surface diameter is from about 2.1 mm to about 2.3 mm. In some embodiments, the pore surface diameter is from about 2.15 mm to about 2.25 mm. In some embodiments, the pore surface diameter is about 2.2 mm. In some embodiments, the pore surface diameter is from about 90%4 mm.

[0048] In some embodiments, the pores have a surface aspect ratio defined as the average width at the sheet-side surface of the opening of the individual pores in the pore pattern divided by the average length at the sheet-side surface of the individual pores in the pore pattern, as viewed from above the sheet-side surface of the felt. In some embodiments, the surface aspect ratio is about 0.3 to about 3. In some embodiments, the surface aspect ratio is about 0.5 to about 2. In some embodiments, the surface aspect ratio is about 0.75 to about 1.5. In some embodiments, the surface aspect ratio is about 1. Where the pore shape is circular, the surface aspect ratio is approximately 1.

[0049] In some embodiments, the pores have a depth defined as the average depth of the individual pores in the pore pattern. Pore depth (p) may be determined by measuring the depth of a pore from the sheet-side surface of the felt to the center of the bottom of the pore (see FIG. 6). In some embodiments, the pore depth is from about 100 microns to about 1000 microns. In some embodiments, the pore depth is from about 300 microns to about 800 microns. In some embodiments, the pore depth is from about 400 microns to about 700 microns. In some embodiments, the pore depth is from about 550 microns to about 650 microns.

[0050] In some embodiments, the pores have a 90% depth diameter (90% p) defined as the average diameter of the individual pores in the pore pattern at 90% of the pore depth. For pore shapes that are non-circular, 90% depth diameter may be determined by averaging the average pore width and the average pore length at 90% of the pore depth. In some embodiments, the ratio of the 90% depth diameter to the surface pore diameter is about 0.2 to about 0.7. In someAttorney Docket No.: GP-23037-WO-PCT embodiments, the ratio of the 90% depth diameter to the surface pore diameter is about 0.3 to about 0.55. In some embodiments, the ratio of the 90% depth diameter to the surface pore diameter is about 0.4 to about 0.5. In some embodiments, the ratio of the 90% depth diameter to the surface pore diameter is about 0.45.

[0051] In some embodiments, the pores have a side-wall angle defined as the average angle of the side-wall of the individual pores in the pore pattern. Pore side-wall angle (a) may be determined by measuring the angle of the side wall from the outer circumference of an individual pore at the sheet-side surface of the felt to the outer circumference of the individual pore at its 50% depth, as offset from a line that is perpendicular to the felt surface (see FIGS.6 and 7). In some embodiments, the pore side-wall angle is from about 20° to about 80°. In some embodiments, the pore side-wall angle is from about 30° to about 70°. In some embodiments, the pore side-wall angle is from about 30° to about 55°. In some embodiments, the pore side- wall angle is from about 40° to about 50°. In some embodiments, the pore side-wall angle is from about 43° to about 47°. In some embodiments, the pore side-wall angle is about 45°.

[0052] The pore geometries described above (e.g., shape, depth, diameter, 90% depth diameter, side-wall angle, etc.) are important to ensure adequate accessibility of the fibers of the paper web into the volume of the apertures of the press felt during wet pressing for maximum dome formation and adequate structural rigidity to maintain the increased caliper resulting from the domes throughout the remainder of the tissue making process. Without wishing to be bound by theory, if the geometries are not as described above, for example the pore depth is too low or high, the side-wall angle too steep or shallow, and / or the ratio of 90% depth diameter to surface pore diameter low or high, it is believed that the resulting domes in the paper sheet would not be ideally defined and / or would not maintain ideal rigidity.

[0053] The pores in the press felt may be configured in a pore pattern made up of different geometries including contact area, pore area, pore pattern MD and CD distance, pore density, pattern offset angle, and the like.

[0054] The press felts disclosed herein have a contact area defined as the percentage of the surface area of the sheet-side surface of the press felt that contacts a paper web when the two come into contact before wet pressing begins (see FIG.8). In other words, the contact area is the surface area of the sheet-side surface of the press felt minus pore area. Percent contact area mayAttorney Docket No.: GP-23037-WO-PCT be determined by measuring the surface area of a sample of the press felt minus the surface area of the sample that is comprised of the individual pores, and dividing by the total surface area of the sample. In some embodiments, the press felt has a contact area of from about 30% to about 90%. In some embodiments, the press felt has a contact area of from about 40% to about 90%. In some embodiments, the press felt has a contact area of from about 40% to about 80%. In some embodiments, the press felt has a contact area of from about 50% to about 80%. In some embodiments, the press felt has a contact area of from about 55% to about 65%. In some embodiments, the press felt has a contact area of about 60%.

[0055] The press felts disclosed herein also have a pore area. The pore area is the inverse of the contact area and is defined by the percentage of the surface area of the sheet-side surface of the press felt that does not contact a paper web when the two come into contact before wet pressing begins (see FIG.8). In other words, the pore area is the surface area of the sheet-side surface of the press felt comprised of the area of the pores. Percent pore area may be determined by measuring the surface area of a sample of the press felt that is comprised of the individual pores, and dividing by the total surface area of the sample. In some embodiments, the press felt has a pore area of from about 10% to about 70%. In some embodiments, the press felt has a pore area of from about 20% to about 60%. In some embodiments, the press felt has a pore area of from about 35% to about 45%. In some embodiments, the press felt has a pore area of about 40%.

[0056] The pore and contact areas may be controlled by a variety of variables related to the geometry of the pores themselves, such as the shape, dimensions thereof, and the geometry of the pores in relation to each other, such as the pore density, the machine and cross-directional distance between pores, and the angle between pores.

[0057] In some embodiments, the press felt has a pore pattern MD distance (ΔMD) defined as the average distance between individual pores in the pore pattern in the machine direction, as viewed from above the sheet-side surface of the felt (see FIG.5). For patterns that are at an offset angle from the cross-machine direction, ΔMD is the average distance between individual pores in the pore pattern in the machine direction measured along the angle normal to offset angle (see FIG 10). In some embodiments, the pore pattern MD distance is from about 200 microns to about 1200 microns. In some embodiments, the pore pattern MD distance is fromAttorney Docket No.: GP-23037-WO-PCT about 500 microns to about 1000 microns. In some embodiments, the pore pattern MD distance is from about 600 microns to about 900 microns.

[0058] In some embodiments, the press felt has a pore pattern CD distance (ΔCD) defined as the average distance between individual pores in the pore pattern in the cross-machine direction, as viewed from above the sheet-side surface of the felt (see FIG.5). For patterns that are at an offset angle from the cross-machine direction, ΔCD is the average distance between individual pores in the pore pattern in the cross-machine direction measured along the offset angle (see FIG 10). In some embodiments, the pore pattern CD distance is from about 200 microns to about 1200 microns. In some embodiments, the pore pattern CD distance is from about 500 microns to about 1000 microns. In some embodiments, the pore pattern CD distance is from about 600 microns to about 900 microns. In some embodiments, the pore pattern CD distance is from about 500 microns to about 2000 microns. In some embodiments, the pore pattern CD distance is from about 700 microns to about 1800 microns. In some embodiments, the pore pattern CD distance is from about 800 microns to about 1000 microns.

[0059] In some embodiments, the press felt has a pore density, defined as the number of individual pores in the pore pattern in a given area. The pore density is largely driven by a combination of the pore area and the pore pattern MD and CD distances. In some embodiments the pore density is from about 1 pore / in2to about 1000 pore / in2. In some embodiments the pore density is from about 10 pore / in2to about 500 pore / in2. In some embodiments the pore density is from about 50 pore / in2to about 400 pore / in2.

[0060] In some embodiments, the press felt has a pore pattern offset angle defined by the angle that the pore pattern is offset from the cross-machine direction. Pore pattern offset angle (OA) may be determined by drawing a line through adjacent pores in the pore pattern that are generally aligned in the cross-machine direction and determining the angle between that line and a line parallel with the cross-machine direction (see FIG.10). In some embodiments, pore pattern offset angle from the cross-machine direction is from about 15° to about 50°. In some embodiments, pore pattern offset angle from the cross-machine direction is from about 20° to about 40°. In some embodiments, pore pattern offset angle from the cross-machine direction is from about 25° to about 35°.Attorney Docket No.: GP-23037-WO-PCT

[0061] FIG.5 depicts a close up of a sample of the pore pattern depicted in the press felt of FIG. 4. The press felt 1 includes a plurality of pores 2 having a pore diameter (d), a circular pore shape, and an aspect ratio of approximately 1. The press felt 1 has a pore pattern MD distance (ΔMD) and a pore pattern CD distance (ΔCD).

[0062] FIG.6 depicts a cross-sectional view of an exemplary press felt 1 comprising a sheet-side surface 3 and a roll-side surface 4, wherein the sheet-side surface 3 comprises a plurality of pores 2 extending into the interior of the press felt towards the roll-side surface 4. The plurality of pores 2 have a pore diameter (d) and a pore depth (p) which is less than the felt thickness (t). The plurality of pores 2 also have a pore side-wall angle (a) defined as the angle from the outer circumference of an individual pore at the sheet-side surface of the felt to the outer circumference of the individual pore at its 50% depth, as offset from a line that is perpendicular to the felt surface. FIG.7 is an SEM image of a cross-section of an exemplary press felt with a pore pattern according to some embodiments of the present disclosure, having pore side-wall angles calculated as described above.

[0063] FIG.8 depicts an exemplary press felt 1 having a plurality of pores 2, as viewed from above the sheet-side surface 3. The press felt 1 has a contact area 5, shown as the grey area around the plurality of pores 2, which contacts a paper web when brought into contact with the press felt 1 before wet pressing begins. Likewise, the press felt 1 has a pore area 6, shown as the white area within the plurality of pores 2, which does not contact a paper web when brought into contact with the press felt 1 before wet pressing begins.

[0064] In some embodiments, particularly where the pores are formed by laser drilling, the pores of the press felts disclosed herein may have a fused structure. In particular, the laser drilling results in the melting and fusing of the fibers that make up the pore area and, in some circumstances, some of the area surrounding the pores on the sheet-side surface. Due to the melted structure of the fibers, the fused areas are substantially fluid impermeable, resulting in decreased air / water permeability of the press felt, and thus a decrease in the ability of the press felt to effectively and efficiently dewater the paper web.

[0065] In some embodiments where the pores and at least some area surrounding the pores on the sheet-side surface of the press felt comprise fused fibers, the press felts disclosed herein may be characterizes as having a fused contact area and a non-fused contact area. The non-fusedAttorney Docket No.: GP-23037-WO-PCT contact area is defined as the percentage of the contact area of the sheet-side surface of the press felt that is not comprised of melted or fused fibers. Non-fused contact area may be determined by measuring the total contact area of a sample of a press felt minus the contact area of the sample that consists of melted / fused fibers, and dividing by the total contact area of the sample (see FIG.9). The fused contact area is the inverse of the non-fused contact area, determining by subtracting the non-fused contact area from 100%. In some embodiments, the press felt has a non-fused contact area of about 50% or greater. In some embodiments, the press felt has a non- fused contact area of greater than about 60%. In some embodiments, the press felt has a non- fused contact area of greater than about 75%. In some embodiments, the press felt has a non- fused contact area of greater than about 90%. In some embodiments, the press felt has a non- fused contact area of about 100%.

[0066] FIG.9 depicts another embodiment of an exemplary press felt 1 having a plurality of pores 2 forming a pore pattern across the sheet-side surface 3, as viewed from above the sheet- side surface. The press felt 1 has a pore area 6, shown as the white area within the plurality of pores. The press felt 1 also includes fused contact areas 7 surrounding the individual pores, shown in black, and the remaining, non-fused contact area 8, shown in grey. Together, fused contact area 7 and non-fused contact area 8 make up the contact area of press felt 1, which contacts a paper web when brought into contact with the press felt 1 before wet pressing begins.

[0067] FIG.10 depicts another embodiment of an exemplary press felt 1 having a plurality of pores 2 forming a pore pattern across the sheet-side surface 3, as viewed from above the sheet- side surface. The press felt 1 has a pore pattern offset angle (OA) from the cross-machine direction.

[0068] FIGS.11 and 12 are images of exemplary press felts according to the present disclosure, as viewed from above the sheet-side surface of the felt. The exemplary press felt of FIG.11 exhibits a surface pore diameter of about 1.2 mm, a pore depth of about 475 mm, and a sidewall angle of about 46°. The exemplary press felt of FIG.11 further exhibits a pore pattern offset angle, but the image in FIG.11 is not shown square to the MD direction, such that the offset angle is not apparent. The exemplary press felt of FIG.11 further exhibits a contact area of about 60%, with a significant non-fused contact area of about 70%. The exemplary press felt of FIG.12 is from Example 1D and exhibits a contact area of about 75%, with a significant non-Attorney Docket No.: GP-23037-WO-PCT fused contact area of about 90%. The exemplary press felt of FIG.12 further exhibits the pore pattern offset angle that is apparent from the image. In contrast, FIG.13 is an image of a comparative felt according to FIG.7 of U.S. Pat. No.11,098,450 B2, as viewed from above the sheet-side surface of the felt, exhibiting no pore pattern offset angle, a low contact area and an almost entirely fused contact area (having a non-fused contact area estimated at about 30%). Accordingly, the inventive press felts of FIGS.11 and 12 according to the description herein would exhibit substantially higher air permeability and thereby improved ability to effectively and efficiently dewater the paper web as compared to that of FIG.7 of U.S. Pat. No.11,098,450 B2.

[0069] The press felts disclosed herein have an air permeability defined as a measure of the ability of air to pass through the thickness of the press felt which, holding all other factors equal, is representative of the ability of the felt to dewater the paper web. A higher air permeability generally corresponds to an increased ability to dewater the press felt. Air permeability may be measured according to TAPPI test method TIP 0404-20. In some embodiments, the press felt has an air permeability of from about 5 cfm / ft2to about 50 cfm / ft2. In some embodiments, the press felt has an air permeability of from about 10 cfm / ft2to about 40 cfm / ft2. In some embodiments, the press felt has an air permeability of from about 15 cfm / ft2to about 35 cfm / ft2. In some embodiments, the press felt has an air permeability of from about 20 cfm / ft2to about 30 cfm / ft2. In some embodiments, the press felt has an air permeability of about 20 cfm / ft2.

[0070] Also disclosed herein are methods of making a paper sheet on a conventional wet-press papermaking machine comprising dewatering a cellulosic web in the press section of a conventional wet-press papermaking machine with a press felt to form a paper sheet. The press felt comprises a sheet-side surface and a roll-side surface, wherein the sheet-side surface comprises a plurality of pores extending into the interior of the press felt towards the roll-side surface as described above. The felt and pores can be characterized by one or more physical attributes set out herein.

[0071] As two non-limiting examples, CWP papermaking machines 10 and 20, depicted in FIGS.1 and 2 respectively, may be employed in the methods disclosed herein. The CWP papermaking machine includes a press section 36 in which a press felt 1 compactively dewaters a cellulosic web 64 by exerting compressive forces, including with pressing rolls and / or shoeAttorney Docket No.: GP-23037-WO-PCT presses. The present disclosure, however, is not limited to the use of pressing rolls and / or shoe presses, and any known method of dewatering a paper web in a CWP papermaking machine with a press felt may be used. In methods of the present application, the press felt should have a sheet-side surface comprising a plurality of pores extending into the interior of the press felt towards a roll-side surface, wherein the felt and pores can be characterized by one or more physical attributes set out herein.

[0072] FIG.14 depicts a cross-sectional view of an interaction between a cellulosic web 9 and a press felt 1 having a plurality of pores 2 across a roll-side surface 3 and extending into the interior of the press felt towards the roll-side surface according to the present disclosure. During dewatering, such as in the press section of a CWP machine, the cellulosic web 9 is contacted with the sheet-side surface 3 of the press felt 1 such that the cellulosic web 9 is drawn into the plurality of pores 2 to form domes 12 in the cellulosic web. FIG.15 depicts a cross-sectional view of the paper sheet 15 resulting therefrom, wherein the paper sheet 9 has domes 12 protruding from a Yankee side 24 towards a felt side surface 23 of the paper sheet 15 corresponding to the apertures in the press felt.

[0073] In some embodiments, the methods disclosed herein further comprise forming the cellulosic web in a forming section of the papermaking machine upstream of the press section. The paper web may be comprised of a variety of furnishes, including softwood, hardwood, or a combination, for example, northern bleached softwood kraft (NBSK), southern bleached softwood kraft (SBSK), northern bleached hardwood kraft (NBHK), southern bleached hardwood kraft (SBHK), and / or bleached eucalyptus kraft (BEK). The paper web may also comprise either virgin fibers or recycled or secondary fibers. The furnish that can be refined or unrefined may optionally include wet end chemistry such as starch, wet strength resin (WSR), temporary wet strength (tWSR), carboxymethylcellulose (CMC), debonders, and softeners.

[0074] Any suitable art-recognized forming scheme may be employed. For example, an extensive but non-exhaustive list of former designs for use in accordance with the present disclosure includes a crescent former, a C-wrap twin wire former, an S-wrap twin wire former, a suction breast roll former, a fourdrinier former, or any art-recognized forming configuration. In some embodiments, the forming section comprises a crescent former. As a non-limiting example, a crescent forming section 32 is depicted in FIGS.1 and 2, as described above. TheAttorney Docket No.: GP-23037-WO-PCT papermaking machine may include homogenous or multi-layer headboxes at many different basis weights and fiber orientations, with all varieties of forming wires, single layer, double layer, and triple layer designs

[0075] In some embodiments, the methods disclosed herein further comprise drying the paper sheet on a Yankee dryer downstream of the press section. Any suitable Yankee dryer configuration may be employed. As a non-limiting example, a drying section 38 comprising a Yankee cylinder 100 and Yankee hood 108 is depicted in FIGS.1 and 2, as described above. Likewise, any suitable art-recognized drying scheme might be employed. In some embodiments, drying may be increased on the Yankee dryer by increasing drying time and / or heat applied as compared to that utilized without the apertured press felt of the present description. Without wishing to be bound by theory, the inventors have found that, when a press felt according to the description is used, the contact area of the press felt decreases relative to a traditional press felt, thereby potentially causing a reduction in dewatering of the cellulosic web in the press section. Similarly, without wishing to be bound by theory, the inventors have found that, when a press felt according to the description is used having pores formed of fused fibers (such as those formed by laser drilling), the air permeability of the press felt decreases relatively to a traditional press felt, thereby causing a reduction in dewatering of the cellulosic web in the press section. Accordingly, increased drying via the Yankee hoods may be desirable in combination with the inventive press felts described herein.

[0076] In some embodiments of the methods disclosed herein, a Yankee coating is applied to the cylinder of the Yankee dryer to assist in the operation of the Yankee dryer. Any suitable art- recognized Yankee coating may be applied to the surface of the Yankee cylinder to assist in adhesion, drying, and release of the paper web. The Yankee coating may comprise one or more of an adhesive, release agent, extender, and / or uniformity agent.

[0077] In some embodiments, the methods disclosed herein further comprise creping the paper sheet from the Yankee dryer with a creping blade. Any suitable art-recognized creping blade configurations and / or creping methods may be employed. As a non-limiting example, a web 64 is creped from the Yankee cylinder 100 of drying section 38 by creping blade 109 as depicted in FIGS.1 and 2 and described above.Attorney Docket No.: GP-23037-WO-PCT

[0078] In some embodiments, the methods disclosed herein further comprise calendering the paper sheet downstream of the Yankee dryer. Calendering may be used to improve sheet smoothness. Any suitable art-recognized calendering methods and / or apparatus may be employed. As a non-limiting example, a calender station 40 with rolls 40(a) and 40(b) to calender the web 64 downstream of drying section 38 as depicted in FIGS.1 and 2 and described above. One benefit of the present invention is that the use of the apertured press felts described herein results in an increase in caliper and bulk of the paper web as compared to a paper web made with a conventional non-apertured press felt. Although subsequent calendering may result in loss of some of the increased caliper due to use of the inventive apertured press felts disclosed herein, the resulting paper sheet will still have a higher caliper (and bulk) following calendering as compared to a paper web made with a conventional non-apertured press felt calendered in the same way.

[0079] In some embodiments, the methods disclosed herein further comprise winding the paper sheet onto a reel downstream of the Yankee dryer. Any suitable art-recognized winding method and / or configuration may be employed. As a non-limiting example, a take-up reel 110, located downstream of drying section 38 and configured to receive and wind web 64 after drying, as depicted in FIGS.1 and 2 and described above.

[0080] In some embodiments, the methods disclosed herein further comprise additional operations following the Yankee dryer, including finishing, converting, embossing, printing, and the like.

[0081] In some embodiments, the methods disclosed herein further comprise embossing the paper sheet downstream of the Yankee dryer. In some embodiments of methods disclosed herein, the paper sheet is not embossed downstream of the Yankee dryer.

[0082] In some embodiments, the paper sheet made using the apertured press-felt according to the present description may be converted into a single-ply paper product.

[0083] In some embodiments, the methods disclosed herein further comprise joining the paper sheet made using the apertured press felt with at least one additional paper sheet to form a multi- ply paper product. Any suitable art-recognized means may be employed to join the paper sheets. In some embodiments, at least one of the paper sheet and the at least one additional paper sheetAttorney Docket No.: GP-23037-WO-PCT are embossed. In some embodiments, the paper sheet is not embossed and the at least one additional paper sheet is embossed. In some embodiments, the at least one additional paper sheet is also formed by the method described above, wherein a cellulosic web is dewatered in the press section of a CWP papermaking machine with an apertured press felt as described herein. In some embodiments, the at least one additional sheet is made using a conventional non-apertured press felt.

[0084] In some embodiments, the methods disclosed herein further comprise joining the paper sheet with at least two additional paper sheets to form a multi-ply paper product. Any suitable art-recognized means may be employed join the paper sheets. In some embodiments, at least one of the paper sheet and the at least two additional paper sheets are embossed. In some embodiments, the paper sheet is not embossed and at least one of the at least two additional paper sheets is embossed. In some embodiments, the paper sheet is not embossed and each of the two additional paper sheets is embossed. In some embodiments, at least one of the at least two additional paper sheets is also formed by the method described above, wherein a cellulosic web is dewatered in the press section of a CWP papermaking machine with an apertured press felt as described herein. In some embodiments, each of the two additional paper sheets is also formed by the method described above, wherein a cellulosic web is dewatered in the press section of a CWP papermaking machine with an apertured press felt as described herein. In some embodiments, neither of the two additional paper sheets is formed by the method described above, wherein a cellulosic web is dewatered in the press section of a CWP papermaking machine with an apertured press felt as described herein, but are instead formed using a conventional non-apertured press felt.

[0085] Also disclosed herein is paper product comprising at least one basesheet made by a process comprising dewatering a cellulosic web in the press section of a conventional wet-press papermaking machine with a press felt to form a paper sheet and converting the paper sheet into a paper product. The press felt comprises a sheet-side surface and a roll-side surface, wherein the sheet-side surface comprises a plurality of pores extending into the interior of the press felt towards the roll-side surface as described above. The felt and pores can be characterized by one or more physical attributes set out herein.Attorney Docket No.: GP-23037-WO-PCT

[0086] As described above, FIG.15 depicts a cross-sectional view of a paper sheet 15 resulting from a process according to the present disclosure. The paper sheet 15 has a felt-side surface with protruding domes 12, resulting from contact of the felt-side surface of the paper sheet with the sheet-side surface of the press felt. As such, the pattern of the domes 12 in the paper sheet corresponds to the pore pattern of the plurality of pores 2 in the press felt according to the present disclosure. The paper sheet 15 also has a Yankee-side surface that opposes the felt-side surface, so named because the Yankee-side surface is the surface of the paper sheet that contacts the Yankee-dryer after pressing and during drying. For this reason, the opposing felt-side surface may also be known as the “air-side” surface. The Yankee-side surface comprises negative protrusions corresponding to the domes on the felt-side surface. When the paper sheet contacts the Yankee dryer, only the flat portion of the sheet contacts the dryer, and the portions of the Yankee-side surface comprising the negative protrusions do not contact the dryer.

[0087] FIG.16 is an image of the felt-side surface of a comparative paper sheet formed with a conventional press felt lacking pores as required of the present disclosure. In contrast, FIG.17 is an image of the felt-side surface of one embodiment of a paper sheet formed with a press felt according to the present disclosure, exhibiting domes corresponding to the pores in the press felt. Likewise, FIG.18 is an image of the Yankee-side surface of one embodiment of a paper sheet formed with a press felt according to the present disclosure, exhibiting negative protrusions corresponding to the domes on the felt-side surface.

[0088] Beneficially, it has been found that, due to the structure of the apertured press felts of the present description (the unique combination of hole geometries and pore pattern geometries as described herein), paper sheets made using those press felts exhibit improved caliper, bulk, and absorbency than those made using conventional felts without the apertured surfaces as described herein. Not only do the resulting domed regions in the paper sheet result in increased thickness but the resulting paper sheet is also believed to comprise regions of differing compactness (density) resulting from the apertured press felts of the present description. In particular, the dome regions of the paper sheet resulting from the apertures of the press felts of the present description are less compact (less dense) than the flat regions of the paper sheets resulting from the flat contact area of the press felts of the present description. Without wishing to be bound byAttorney Docket No.: GP-23037-WO-PCT theory, it is believed that the lower density in the dome structures result in increased absorbency of the paper sheet.

[0089] The inventors surprisingly also found a unique fiber density pattern in the dome structures of paper products made using the apertured press felts according to the present disclosure. To characterize paper product density, three-dimensional X-ray micro-computed tomographic (XR-µCT) representations obtained from synchrotron or other laboratory instruments technique can be used to provide an approximation of the local density in paper products. Specifically, with the technique described below, a perpendicular fiber density can be determined at a center surface of a paper product. That the fiber density may vary in the out-of- plane direction due to embossments, creping, drying features, etc.

[0090] With the fiber density determination technique, XR-µCT data sets are received after they have undergone a Radon Transform or a John Transform to convert radially projected X-ray images into three-dimensional data sets consisting of stacks of two-dimensional gray level images. For example, paper product data received from the synchrotron at the European Synchrotron Radiation Facility in Grenoble, France, consists of 2000 slices, each with dimensions of 2000 x ~800 pixels with eight-bit gray level values. The gray level values represent the attenuation of mass, which, for a material of a relatively uniform molecular mass, closely approximates the three-dimensional distribution of mass or formation. Paper products consist principally of cellulosic fibers, so an assumption of constant X-ray attenuation coefficient, and therefore a direct relationship between gray level and mass, is valid.

[0091] In order to obtain representative tomographic data sets, the following segmentation process (a process which shows the separation of different phases of material (i.e., cellulose fibers and air (void) space) in a paper product sample) can be employed using the open software called ImageJ which is a public domain image processing program developed at the United States National Institute of Health. Binarization is utilized as the primary method of segmentation. Slices may also be subjected to filtering processes to remove speckling, or thresholding. All slices are treated in the same manner, so that a data set is generated that clearly distinguishes between fiber mass and void space.

[0092] Relative density of a paper product sample can be calculated from the preprocessed XR- µCT data sets by first generating surfaces that approximate the upper and lower boundaries ofAttorney Docket No.: GP-23037-WO-PCT the sample, and then calculating a center surface between the two. Surface normal vectors, which are determined at each position within the center surface, are then used to determine the mass per volume within an area that is 1 × 1 pixels times the distance (in pixels) between the upper and lower surface along the surface normal vector. All calculations can be performed using MATLAB® by MathWorks Inc. of Natick, Massachusetts. A specific procedure includes surface determination, surface normal and three-dimensional thickness, three-dimensional density, and three-dimensional density representations, as will now be described.

[0093] For surface determination, slices in the XR-µCT data sets are X-Z projections where the X-Y plane is the principal plane of the sample and is the same plane formed by the MD or CD. Therefore, the Z-axis is perpendicular to the X-Y plane and each slice represents a unit step in the Y direction. For each X position within each slice, the gray level values exceeding a limiting a threshold value are identified. Thus, each slice will produce a curve connecting the maximum (upper) and minimum (lower) positions of the fibers indicated in the slice.

[0094] A robust three-dimensional smoothing spline function can be applied to each surface. An algorithm for performing this function is described by D. Garcia, Computational Statistics & Data Analysis, 54:1167-1174 (2010), the disclosure of which is incorporated by reference in its entirety. The smoothing parameter can be varied to produce a series of files that provide a range of surface smoothness that presents individual fiber detail to a greater or lesser extent.

[0095] Three-dimensional surface normal can be calculated at each vertex within the smoothed center surface using the MATLAB® function “surfnorm.” The algorithm is based on a cubic fit of the x, y, and z matrices. Diagonal vectors can be computed and crossed to form the normal. Line segments, parallel to the surface normal that pass through each vertex and terminate at the upper and lower smoothed surfaces can be used to determine the thickness of a paper product sample in a direction perpendicular to the center surface.

[0096] The three-dimensional relative fiber density is determined along a pathway perpendicular to the center surface by assuming a right rectangular prism with two dimensions being one pixel and the third as the length of the line segment extending from the two external smoothed surfaces through the vertex. The mass contained within that volume is determined as the voxels have a finite mass as indicated by the gray level value from the tomographic data set. Thus, the maximum relative density at a vertex is equal to one is all of the voxels along the line segmentAttorney Docket No.: GP-23037-WO-PCT contain a gray level value of 255. The maximum value for the cell walls of cellulosic fibers is taken to be 1.50 g / cm3.

[0097] A convenient representation of the three-dimensional fiber density can be made by mapping the fiber density in four dimensions using the smoothed center surface to shower the extent of out-of-plane deformation for the sample and indicating the three-dimensional density as a spectral plot with values at each location within the map. These maps may be shown as relative density with maximum values of 1, or normalized to the density of cellulose with a maximum of 1.50 g / cm3as indicated.

[0098] Using the above-described method, the inventors generated the density maps in FIGs. 19A and 19B. FIG.19A is a density map of a comparative paper sheet made with a press felt according to FIG.7 of U.S. Pat. No.11,098,450 B2. In contrast, FIG.19B is a density map of exemplary a paper sheet formed with a press felt according to Example 1A of the present disclosure. The inventors surprisingly found that the density of the domes differs between the paper sheet made with a press felt according to FIG.7 of U.S. Pat. No.11,098,450 B2 (Fig.19A) and those of the inventive paper sheet (Fig.19B). In the comparative sheet, the domes are typically high fiber density areas, suggesting that the fiber was piling up in the dome area. Likewise, the surrounding flat areas are typically of lower fiber density. In contrast, the raised dome structures in the inventive paper sheet typically show low fiber density as the sheet is stretched or elongated into the felt. Meanwhile, the surrounding flat areas show typically higher fiber density. In other words, the inventive paper sheet presents in the opposite manner as the comparative paper sheet made with a press felt according to FIG.7 of U.S. Pat. No.11,098,450 B2. Without wishing to be bound by theory, this difference is likely attributed to the design improvements in the pore and pattern geometries described herein, as well as the inventive felt pore permeability and low fused surface area.

[0099] The present inventors have further surprisingly found an unexpected synergy develops when a paper sheet that has made using an apertured press felt according to the present invention is subsequently creped from a Yankee dryer. Creping a paper sheet from the Yankee dryer is known to impart crepe bars (wave like formations) on the resultant paper product. The inventors have found that, upon creping the paper sheet from the Yankee dryer in the methods of the present disclosure, crepe bars form only on the relatively flat surface of the paper sheetAttorney Docket No.: GP-23037-WO-PCT (corresponding to the contact area on the apertured press felt) but crepe bars are not formed on the raised dome structures of the paper sheet (corresponding to the apertures on the press felt). This differentiation in crepe can be seen in the paper sheet surfaces shown in FIGS.17 and 18 and in the cross-section pictured in FIG.21. In contrast, paper products made with conventional, non-apertured felts or even with textured fabrics in a through-air-dried or NTT process, exhibit crepe folds uniformly distributed across the surface of the sheet. Without wishing to be bound by theory, it is believed that that the unique combination of crepe bars and dome structure leads to leads to increased performance, or more specifically, higher caliper and equivalent softness or higher softness and equivalent caliper, as a function of dome integrity preservation combined with the planar contact area foreshortening and internal delamination during the creping process. In addition, the difference in compaction throughout the paper sheet described above is believed to beneficially result in optimization of the creping process, including improving handfeel development and optimization of the domed structure for caliper and absorbency.

[0100] FIG.20A is an X-Ray image of a cross-section of a comparative paper sheet formed with a conventional, non-apertured press felt (the comparative control felt used against Example 1A). Likewise, FIG.20B is an X-Ray image of a cross-section of a comparative paper sheet formed with a press felt as shown in FIG.7 of U.S. Pat. No.11,098,450 B2. In contrast, FIGS.20C and 21 are X-Ray images of a cross-section of an exemplary paper sheet formed with a press felt according to the present disclosure, exhibiting domes corresponding to the pores in the press felt. The press felt show in Figure 20C is that of Example 1A. As can be seem from FIGs.20A and 21, the domes of the exemplary paper sheets lack crepe bars, while the flat sections of the paper sheet between domes exhibit crepe bars.

[0101] In some embodiments, the paper product is an absorbent product. In some embodiments, the paper product is suitable for use in personal hygiene, domestic or commercial cleaning, or in other consumer applications. In some embodiments, the paper product is a tissue, towel, or napkin product. In some embodiments, the paper product may be a tissue product, such as a bath tissue, facial tissue, baby tissue, or the like. In some embodiments, the paper product may be a towel product, such as a paper towel, wipe, or the like. In some embodiments, the paper product may be a napkin, a table cover, or the like.Attorney Docket No.: GP-23037-WO-PCT

[0102] In some embodiments, the paper product is a bath tissue. In some embodiments, the paper product is a facial tissue. In some embodiments, the paper product is a paper towel. In some embodiments, the paper product is a napkin.

[0103] In some embodiments, the paper product has a caliper. Caliper refers to the thickness of a paper sheet and may be determined by physical measurement of the paper sheet with a manual caliper, electronic thickness tester, or other suitable measurement device (mils / 8 sheet). In some embodiments, the paper product exhibits a in caliper at least about 5% greater, at least about 10% greater, at least about 15% greater, or at least about 20% greater than the caliper of a paper product made by an identical process, but with a conventional non-apertured press felt.

[0104] In some embodiments, the paper product has a bulk. Bulk refers to the caliper of a paper sheet, normalized by its basis weight, and may be determined by dividing the thickness of a sample by its weight (cm3 / g). In some embodiments, the paper product exhibits a bulk at least about 15% greater, at least about 25% greater, or at least about 35% greater than the bulk of a paper product made by an identical process, but with a conventional non-apertured press felt.

[0105] In some embodiments, the paper product has a SAT capacity (g / m2). SAT capacity is a measure of a paper sheet’s ability to absorb water and may be determined by any suitable gravimetric absorbency testing system. In some embodiments, the paper product exhibits a SAT capacity at least about 20% greater, at least about 35% greater, or at least about 50% greater than the SAT capacity of a paper product made by an identical process, but with a conventional non-apertured press felt.

[0106] In some embodiments, the paper product is a single-ply product. In some embodiments, the paper product is a multi-ply product. In some embodiments, the paper product is a two-ply product comprising the paper sheet and a second paper sheet. In some embodiments, at least one of the paper sheet and the second paper sheet are embossed. In some embodiments, the paper sheet is not embossed and the second paper sheet is embossed.

[0107] In some embodiments, the paper product is a two-ply product comprising the paper sheet and a second paper sheet, wherein the second paper sheet has also been made with anAttorney Docket No.: GP-23037-WO-PCT apertured press felt as described herein. In some embodiments, the second sheet is made using a conventional non-apertured press felt.

[0108] In some embodiments, the paper product is a two-ply product wherein the paper sheet is unembossed and is joined with a second embossed paper sheet made using a conventional non-apertured press felt. In some embodiments, the paper product is a two-ply product wherein the paper sheet is embossed and is joined with a second embossed paper sheet made using a conventional non-apertured press felt. In some embodiments, the paper product is a two-ply product wherein the paper sheet is joined with a second embossed paper sheet made using an apertured press felt as disclosed herein, and wherein at least one of the two sheets is embossed.

[0109] In some embodiments, the paper product is a three-ply product comprising the paper sheet, a second paper sheet, and a third paper sheet. In some embodiments, at least one of the paper sheet, the second paper sheet, and the third paper sheet is embossed. In some embodiments, the paper sheet is not embossed and at least one of the second paper sheet and the third paper sheet is embossed. In some embodiments, the paper sheet is not embossed and both of the second paper sheet and the third paper sheet are embossed.

[0110] In some embodiments, the paper product is a three-ply product wherein the paper sheet is unembossed and is joined with a second paper sheet and a third embossed paper sheet, each made using a conventional non-apertured press felt, and at least one of which is embossed. In some embodiments, the paper product is a three-ply product wherein the paper sheet is embossed and is joined with a second embossed paper sheet and a third embossed paper sheet, each made using a conventional non-apertured press felt. In some embodiments, the paper product is a three-ply product wherein the paper sheet is unembossed and is joined with a second paper sheet and a third paper sheet, at least one of which is made using an apertured press felt as disclosed herein, and at least one of which is embossed. In some embodiments, the paper product is a three-ply product wherein the paper sheet is embossed and is joined with a second paper sheet and a third paper sheet, at least one of which is made using an apertured press felt as disclosed herein, and at least one of which is embossed.

[0111] Descriptions of the disclosed embodiments are not exhaustive and are not limited to the precise forms or exemplary embodiments disclosed. Modifications and adaptations of theAttorney Docket No.: GP-23037-WO-PCT exemplary embodiments will be apparent from consideration of the specification and practice of the disclosed embodiments.

[0112] Without limitation, some embodiments of the disclosure include:

[0113] Exemplary Press Felts

[0114] Embodiment A: A press felt for use in a conventional wet-press papermaking machine, wherein the press felt comprises a sheet-side surface and a roll-side surface; wherein the sheet-side surface comprises a plurality of pores extending into the interior of the press felt towards the roll-side surface.

[0115] Embodiment B: The press felt according to Embodiment A, wherein the plurality of pores have a pore depth from about 100 microns to about 1000 microns, for example, from about 300 microns to about 800 microns, from about 400 microns to about 700 microns, or from about 550 microns to about 650 microns.

[0116] Embodiment C: The press felt according to any of Embodiments A-B, wherein the plurality of pores have a pore side-wall angle from 20° to about 80°, for example, from about 30° to about 70°, from about 30° to about 55°, from about 40° to about 50°, from about 43° to about 47°, or about 45°.

[0117] Embodiment D: The press felt according to any of Embodiments A-C, wherein the press felt has a contact area of from about 30% to about 90%, for example, from about 40% to about 90%, from about 40% to about 80%, from about 50% to about 80%, from about 55% to about 65%, or about 60%.

[0118] Embodiment E: The press felt according to any of Embodiments A-D, wherein the plurality of pores have a pore surface diameter from about 0.5 mm to about 3.0 mm, for example, from about 1.0 mm to about 2.4 mm.

[0119] Embodiment F: The press felt according to any of Embodiments A-E, wherein the plurality of pores have a pore surface diameter from about 0.5 mm to 1.8 mm, for example, from about 1.0 mm to about 1.5 mm, from about 1.1 mm to about 1.3 mm, from about 1.15 mm to about 1.25 mm, or about 1.2 mm.Attorney Docket No.: GP-23037-WO-PCT

[0120] Embodiment G: The press felt according to any of Embodiments A-E, wherein the plurality of pores have a pore surface diameter from about 1.3 mm to about 1.5 mm, for example, from about 1.35 mm to about 1.45 mm, or about 1.4 mm.

[0121] Embodiment H: The press felt according to any of Embodiments A-E, wherein the plurality of pores have a pore surface diameter from 1.5 mm to about 2.0 mm, for example, from about 1.7 mm to about 1.9 mm, from about 1.75 mm to about 1.85 mm, or about 1.8 mm.

[0122] Embodiment I: The press felt according to any of Embodiments A-E, wherein the plurality of pores have a pore surface diameter from about 1.8 mm to about 3.0 mm, for example, from about 2.0 mm to about 2.5 mm, from about 2.1 mm to about 2.3 mm, from about 2.15 mm to about 2.25 mm, or about 2.2 mm.

[0123] Embodiment J: The press felt according to any of Embodiments A-I, wherein the plurality of pores have a ratio of 90% depth diameter to surface pore diameter of from about 0.3 to about 0.55

[0124] Embodiment K: The press felt according to any of Embodiments A-J, wherein the press felt has a non-fused contact area of greater than about 50%, for example, greater than about 60%, greater than about 75%, greater than about 90%, or about 100%.

[0125] Embodiment L: The press felt according to any of Embodiments A-K, wherein the press felt has a pore pattern offset angle from about 15° to about 50°, for example, from about 20° to about 40°, or from about 25° to about 35°.

[0126] Embodiment M: The press felt according to any of Embodiments A-L, wherein the press felt has a pore pattern MD distance from about 200 microns to about 1200 microns, for example, from about 500 microns to about 1000 microns, or from about 600 microns to about 900 microns.

[0127] Embodiment N: The press felt according to any of Embodiments A-M, wherein the press felt has a pore pattern CD distance from about 500 microns to about 2000 microns, for example, from about 700 microns to about 1800 microns, from about 800 microns to about 1000 microns.Attorney Docket No.: GP-23037-WO-PCT

[0128] Embodiment O: The press felt according to any of Embodiments A-N, wherein the press felt has a pore pattern CD distance of from about 200 microns to about 1200 microns, for example, from about 500 microns to about 1000 microns, or from about 600 microns to about 900

[0129] Embodiment P: The press felt according to any of Embodiments A-O, wherein the press felt has a pore density from about 1 pore / in2to about 1000 pore / in2, for example, about 10 pore / in2to about 500 pore / in2, or from about 50 pore / in2to about 400 pore / in2.

[0130] Embodiment Q: The press felt according to any of Embodiments A-P, wherein the plurality of pores have a sheet-side surface shape chosen from circular and oval.

[0131] Embodiment R: The press felt according to any of Embodiments A-Q, wherein the plurality of pores have a surface aspect ratio from about 0.3 to about 3, for example, from about 0.5 to about 2, from about 0.75 to about 1.5, or about 1.

[0132] Embodiment S: The press felt according to any of Embodiments A-R, wherein the press felt has an air permeability of from about 5 cfm / ft2to about 50 cfm / ft2, for example, from about 10 cfm / ft2to about 40 cfm / ft2, from about 15 cfm / ft2to about 35 cfm / ft2, from about 20 cfm / ft2to about 30 cfm / ft2, or about 20 cfm / ft2.

[0133] Embodiment T: The press felt according to any of Embodiments A-S, wherein the pores are formed by laser drilling.

[0134] Exemplary Methods

[0135] Embodiment AA: A method of making a paper sheet on a conventional wet-press papermaking machine comprising dewatering a cellulosic web in the press section of a conventional wet-press papermaking machine with a press felt to form a paper sheet, wherein the press felt comprises a sheet-side surface and a roll-side surface; wherein the sheet-side surface comprises a plurality of pores extending into the interior of the press felt towards the roll-side surface.

[0136] Embodiment BB: The method according to Embodiment AA, wherein the press felt is in accordance with any of Embodiments A-T.Attorney Docket No.: GP-23037-WO-PCT

[0137] Embodiment CC: The method according to any of Embodiments AA-BB, further comprising forming the cellulosic web in a forming section of the papermaking machine upstream of the press section, wherein the forming section comprises a configuration chosen from twin wire and crescent.

[0138] Embodiment DD: The method according to any of Embodiments AA-CC, further comprising drying the paper sheet on a Yankee dryer downstream of the press section.

[0139] Embodiment EE: The method according to any of Embodiments AA-DD, wherein the paper sheet is adhered to the Yankee dryer with an adhesive.

[0140] Embodiment FF: The method according to any of Embodiments AA-EE, further comprising creping the paper sheet from the Yankee dryer with a creping blade.

[0141] Embodiment GG: The method according to any of Embodiments AA-FF, further comprising calendering the paper sheet.

[0142] Embodiment HH: The method according to any of Embodiments AA-GG, further comprising embossing the paper sheet.

[0143] Embodiment II: The method according to any of Embodiments AA-HH, wherein the paper sheet is not embossed.

[0144] Embodiment JJ: The method according to any of Embodiments AA-II, further comprising joining the paper sheet with at least one additional paper sheet to form a multi-ply paper product.

[0145] Embodiment KK: The method according to any of Embodiments AA-JJ, wherein the at least one additional paper sheet is also formed by the method according to Embodiments AA-DD.

[0146] Embodiment LL: The method according to any of Embodiments AA-KK, wherein the paper sheet is not embossed and wherein the at least one additional paper sheet is embossed.

[0147] Embodiment MM: The method according to any of Embodiments AA-LL, further comprising joining the paper sheet with at least two additional paper sheets to form a multi-ply paper product.Attorney Docket No.: GP-23037-WO-PCT

[0148] Embodiment NN: The method according to any of Embodiments AA-MM, wherein at least one of the at least two additional paper sheets is also formed by the method according to Embodiments AA-DD.

[0149] Embodiment OO: The method according to any of Embodiments AA-NN, wherein the paper sheet is not embossed and wherein at least one of the at least two additional paper sheets is embossed.

[0150] Embodiment PP: The method according to any of Embodiments AA-OO, wherein the resultant paper sheet has a generally flat surface with raised dome regions.

[0151] Embodiment QQ: The method according to any of Embodiments AA-PP, wherein the resultant paper sheet has a generally flat surface with raised dome regions; and wherein the generally flat surface exhibits crepe bars but the raised dome regions do not exhibit crepe bars.

[0152] Exemplary Products

[0153] Embodiment AAA: A paper product made by a process comprising dewatering a cellulosic web in the press section of a conventional wet-press papermaking machine with a press felt to form a paper sheet, wherein the press felt comprises a sheet-side surface and a roll- side surface; wherein the sheet-side surface comprises a plurality of pores extending into the interior of the press felt towards the roll-side surface; and converting the paper sheet into a paper product.

[0154] Embodiment BBB: The paper product according to Embodiment AAA, wherein the press felt is in accordance with any of Embodiments A-T.

[0155] Embodiment CCC: The paper product according to any of Embodiments AAA- BBB, wherein the product includes a generally flat surface with raised dome regions.

[0156] Embodiment DDD: The paper product according to any of Embodiments AAA- CCC, wherein the generally flat surface exhibits crepe bars but the raised dome regions do not exhibit crepe bars.

[0157] Embodiment EEE: The paper product according to any of Embodiments AAA- DDD, wherein the product is a tissue, towel, or napkin product.Attorney Docket No.: GP-23037-WO-PCT

[0158] Embodiment FFF: The paper product according to any of Embodiments AAA- EEE, wherein the product is a bath tissue.

[0159] Embodiment GGG: The paper product according to any of Embodiments AAA- FFF, wherein the product is a paper towel.

[0160] Embodiment HHH: The paper product according to any of Embodiments AAA- GGG, wherein the product is a napkin.

[0161] Embodiment III: The paper product according to any of Embodiments AAA- HHH, wherein the product is a two-ply product comprising the paper sheet and a second paper sheet.

[0162] Embodiment JJJ: The paper product according to any of Embodiments AAA-III, wherein both the paper sheet and the second paper sheet are embossed.

[0163] Embodiment KKK: The paper product according to any of Embodiments AAA- JJJ, wherein the paper sheet is not embossed and wherein the second paper sheet is embossed.

[0164] Embodiment LLL: The paper product according to any of Embodiments AAA- KKK, wherein the second paper sheet has also been made by the process of Embodiments AAA- DDD.

[0165] Embodiment MMM: The paper product according to any of Embodiments AAA- LLL, wherein the product is a three-ply product comprising the paper sheet, a second paper sheet, and a third paper sheet.

[0166] Embodiment NNN: The paper product according to any of Embodiments AAA- MMM, wherein the paper sheet is not embossed and wherein at least one of the second paper sheet and the third paper sheet is embossed.

[0167] Embodiment OOO: The paper product according to any of Embodiments AAA- NNN, wherein the paper sheet is embossed and wherein at least one of the second paper sheet and the third paper sheet is embossed.Attorney Docket No.: GP-23037-WO-PCT

[0168] Embodiment PPP: The paper product according to any of Embodiments AAA- OOO, wherein at least one of the second paper sheet and the third paper sheet has also been made by the process of Embodiments AAA-DDD.

[0169] Embodiment QQQ: The paper product according to any of Embodiments AAA- PPP, wherein the product exhibits a caliper (mils / 8 sheet) at least about 5% greater than the caliper of a paper product made by an identical process, but with a conventional non-apertured press felt.

[0170] Embodiment RRR: The paper product according to any of Embodiments AAA- QQQ, wherein the product exhibits a bulk (cm3 / g) at least about 15% greater than the bulk of a paper product made by an identical process, but with a conventional non-apertured press felt.

[0171] Embodiment SSS: The paper product according to any of Embodiments AAA- RRR, wherein the product exhibits a SAT capacity (g / m2) at least 20% greater than the SAT capacity of a paper product made by an identical process, but with a conventional non-apertured press felt. EXAMPLES Example 1

[0172] Exemplary press felts according to the present disclosure were formed with the properties shown in Table 1 below. Table 1 Ex 1A Ex 1B Ex 1C Ex 1D Pore Side-Wall Angle 48° 47° 70° 30-35° Pore Depth (µm) 500-530 600 600 400-500 Pore Diameter (mm) 1.2 1.4 1.0 0.9 Contact Area 58% 58% 75% 75% MD Distance (µm) 439 503 752 696 CD Distance (µm) 439 503 753 696 Pattern Offset Angle 27° 33° 29° 31° Example 2Attorney Docket No.: GP-23037-WO-PCT

[0173] In Example 2, six products were formed on a CWP papermaking machine. Three comparative products as described below—comparative value tissue, comparative premium tissue, and comparative towel—were formed using a conventional non-apertured press felt. Three inventive products—apertured press felt value tissue, apertured press felt premium tissue, and apertured press felt towel—were prepared by substantially identical processes, but using the inventive press felt Ex 1A of Example 1 above instead of a conventional non-apertured press felt. The control press felts were identical in structure to the press felt of Ex 1A, but did not include apertures as described herein.

[0174] The basesheets were manufactured on a high-speed pilot paper machine configured with a TW-C former using conventional wet press technology, then converted to multi-ply prototypes on a high-speed pilot converting line, and configured with a multi-roll unwind, dual-emboss, and glue-lamination converting technology. The sheets were pressed to the Yankee at a 40% consistency. Thereafter the sheets were dried and creped from the Yankee, and wound onto the reel.

[0175] The value tissue basesheets (both comparative and inventive) utilized a fiber ratio of 65% SBSK and 35% BEK. Target specifications, including a basesheet basis weight curve ranging from 10 lb / rm to 11 lb / rm to 12 lb / rm, are included in Table 2 below. Creping and coating were representative of what one skilled in the art would consider for a reel moisture target of 4-5%. Wet end chemistry included starch (4 lb / t to static mixer before stuff box).Attorney Docket No.: GP-23037-WO-PCT Table 2 Parameter Value Tissue Target + / - Basis Weight (lb / rm) 10 11 0.3 12 Caliper (mil / 8sht) Max - MD Tensile (g / 3in) 800 100 CD Tensile (g / 3in) 350 50 MD Stretch (%) 24 3

[0176] Value tissue was converted into finished product rolls in a 2-ply format with high visibility structure emboss technology (i.e., top layer embossed, bottom layer unembossed) with glue lamination. All rolls were held at a constant emboss penetration. In the inventive apertured value tissue product, both plies were formed using the inventive apertured press felt. Target finished product specifications are included in Table 3 below. Table 3 Parameter Value Tissue Target + / - Basis Weight (lb / rm) 20 22 0.6 24 Caliper (mil / 8sht) Max - MD Tensile (g / 3in) 1260 200 CD Tensile (g / 3in) 480 75 MD Stretch (%) 19 4

[0177] The premium tissue basesheets (both comparative and inventive) utilized a fiber ratio of 30% NBSK and 70% BEK. Target specifications, including a basesheet basis weightAttorney Docket No.: GP-23037-WO-PCT curve ranging from 11.6 lb / rm to 12.1 lb / rm to 12.6 lb / rm, are included in Table 4 below. Creping and coating were representative of what one skilled in the art would consider for a reel moisture target of 2-3%. Wet end chemistry included starch (2 lb / t to static mixer before stuff box), tWSR (2 lb / t to air layer fam pump), and debonder (as needed to stock pumps). Table 4 Parameter Premium Tissue Target + / - Basis Weight (lb / rm) 11.6 12.1 0.2 12.6 Caliper (mil / 8sht) Max - MD Tensile (g / 3in) 500 50 CD Tensile (g / 3in) 200 50 CD Wet Tensile (g / 3in) 25 10 MD Stretch (%) 28 3

[0178] Premium tissue was converted into finished product rolls in a 3-ply format with high visibility structure emboss technology (i.e., middle and top layer embossed together, bottom layer unembossed) with glue lamination. All rolls were held at a constant emboss penetration. In the inventive apertured premium tissue product, all three plies were formed using the inventive apertured press felt. Target finished product specifications are included in Table 5 below.Attorney Docket No.: GP-23037-WO-PCT Table 5 Parameter Premium Tissue Target + / - Basis Weight (lb / rm) 30 33 0.6 36 Caliper (mil / 8sht) Float - MD Tensile (g / 3in) 1250 100 CD Tensile (g / 3in) 425 50 CD Wet Tensile (g / 3in) 63 10 MD Stretch (%) 20 4 Sheet Count 254 5 Roll Diameter (in) Float - Sheet Length (in) 4 0.1 Sheet Width (in) 3.8 0.1

[0179] The towel basesheets (both comparative and inventive) utilized a fiber ratio of 100% SBSK. Target specifications, including a basesheet basis weight curve ranging from 12.5 lb / rm to 13.5 lb / rm to 14.5 lb / rm, are included in Table 6 below. Creping and coating were representative of what one skilled in the art would consider for a reel moisture target of 4-5% for towel. Wet end chemistry included WSR (10 lb / t to stock static mixer) and CMC (3 lb / t to static mixer before stuff box).Attorney Docket No.: GP-23037-WO-PCT Table 6 Parameter Towel Target + / - Basis Weight (lb / rm) 12.5 13.5 0.3 14.5 Caliper (mil / 8sht) Float - MD Tensile (g / 3in) 2000 200 CD Tensile (g / 3in) 1800 200 CD Wet Tensile (g / 3in) 425 50 MD Stretch (%) 22 3

[0180] Value towel was converted into finished product rolls in a 2-ply format with high visibility structure, nested and back ply emboss technology (i.e., both layers embossed) with glue lamination. All rolls were held at a constant emboss penetration. In the inventive apertured value towel product, both plies were formed using the inventive apertured press felt. Target finished product specifications are included in Table 7 below.Attorney Docket No.: GP-23037-WO-PCT Table 7 Parameter Towel Target + / - Basis Weight (lb / rm) 25 27 0.6 29 Caliper (mil / 8sht) Float - MD Tensile (g / 3in) 3200 500 CD Tensile (g / 3in) 2000 500 CD Wet Tensile (g / 3in) 500 150 Sheet Count 110 3 Roll Diameter (in) Float - Sheet Length (in) 6 0.1 Sheet Width (in) 11 0.1

[0181] Representative properties of the products of Example 2 are illustrated in Tables 8A and 8B below. As can be seen from the data in Tables 8A and 8B, the inventive products prepared with apertured press felts according to the present disclosure exhibited significant increases in caliper, bulk, and SAT capacity / rate as compared with the comparative products without exhibiting significant deterioration in MD, CD, or GM tensile strength or softness.Attorney Docket No.: GP-23037-WO-PCT Table 8A Basis MD CD GM Caliper Bulk Bulk Product Weight 3 Tensile Tensile Tensile (mil / 8sht) (cm / g) %Δ (lb / rm) (g / 3in) (g / 3in) (g / 3in) Comp. 9.9 41.4 8.1 - 751 342 506 Value 11.0 42.6 7.6 - 849 394 578 Tissue 11.7 45.4 7.6 - 841 353 545 Apertured 10.2 52.7 10.1 24% 852 379 568 Value 11.2 58.2 10.1 34% 769 350 519 Tissue 11.8 59.0 9.7 29% 837 370 557 Comp. 11.8 47.4 7.9 - 492 198 312 Premium 12.0 46.6 7.6 - 502 210 325 Tissue 12.6 49.7 7.7 - 509 207 325 Apertured 11.6 65.4 11.0 39.8% 514 188 311 Premium 12.2 63.3 10.2 34.4% 552 233 359 Tissue 12.6 65.6 10.1 31.7% 547 237 360 12.6 39.5 6.1 - 1996 1781 1885 Comp. 13.4 38.6 5.6 - 2288 2134 2209 Towel 14.6 46.9 6.3 - 2043 1794 1915 12.7 42.2 6.5 6% 1978 1738 1854 Apertured 13.4 44.7 6.5 15% 1987 1823 1903 Towel 14.5 48.0 6.5 3% 2119 1872 1992Attorney Docket No.: GP-23037-WO-PCT Table 8B MD CD SAT SAT SAT TSA SAT Product Stretch Stretch Capacity Rate Rate Hand- (%) (%) (g / m2%Δ ) (g / s0.5) %Δ feel Comp. 28.1 8.9 251 - 0.20 - 83.6 Value 27.9 7.9 257 - 0.20 - 83.8 Tissue 29.6 8.6 279 - 0.22 - 83.6 Apertured 31.1 6.3 278 11% 0.26 28% 86.1 Value 27.5 5.7 283 10% 0.26 33% 86.6 Tissue 28.7 5.9 291 4% 0.26 21% 84.4 Comp. 31.3 6.8 425 - 0.32 - 94.2 Premium 30.6 7.0 - - - - 94.3 Tissue 29.7 6.8 446 - 0.35 - 94.8 Apertured 29.2 7.6 538 27% 0.50 57% 93.4 Premium 31.1 6.5 538 - 0.52 - 92.5 Tissue 31.5 6.8 545 22% 0.46 31% 94.5 29.0 5.1 204 - 0.05 - - Comp. 29.0 4.8 212 - 0.05 - - Towel 25.8 4.8 245 - 0.06 - - 26.7 5.2 225 10% 0.08 47% - Apertured 27.7 5.6 249 18% 0.08 47% - Towel 28.0 5.6 229 -6% 0.08 24% - Example 3

[0182] In Example 3, three tissue products were made using the inventive press felt Ex 1B of Example 1 above.

[0183] Basesheets were manufactured on a high-speed pilot paper machine configured with a TW-C former using conventional wet press technology. The paper machine headbox wasAttorney Docket No.: GP-23037-WO-PCT set up to stratify the furnish with a 50:50 layer weight for premium fiber blended prototypes and homogeneous for the SBSK and Recycled fiber prototypes. The forming wires used were industry standard.

[0184] The premium tissue product utilized a 70% BEK and 30% NBSK with a 100% BEK top layer. To influence bulk and absorbency, basis weight was adjusted from 10 lb / rm to 15 lb / rm to 18 lb / rm. The products were produced to target specifications found in Table 9. Table 9 Parameter 2-ply Tissue Target + / - Basis Weight (lb / rm) 12-13 0.5 MD Tensile (g / 3in) 475-575 100 CD Tensile (g / 3in) 200-250 35 MD Stretch (%) 26-30 5

[0185] Representative properties of the products in Example 3 are illustrated in Table 10 below. As can be seen from the data therein, the inventive products exhibited significant increases in caliper and bulk, as compared industry-standard products made by conventional wet press tissue making.Attorney Docket No.: GP-23037-WO-PCT Table 10 Basis Caliper Bulk Weight Apertured 10 59 11.512 BEK / NBSK 15 72 9.366 18 78 8.455 Apertured 10 52 10.147 SBSK 15 66 8.586 18 80 8.672 Apertured 10 58 11.317 Recycled 15 78 10.147 18 83 8.997 Example 4

[0186] In Example 4, an inventive tissue product was made using press felt Ex 1C of Example 1 above and comparative tissue product was made using similar process conditions and raw materials (such as the same fiber composition, similar strength control strategies, the same forming set-up and conditions, a similar chemical utilization approach, the same pressing set-up and conditions, identical reel moisture targets, and similar converting, embossing and winding conditions) but with a control press felt. The control press felt was identical in structure to the press felt of Ex 1C, but did not include apertures as described herein.

[0187] As can be seen from the data of Table 11 below, when the inventive tissue product was targeted to achieve an equivalent caliper relative to the control (equal bulk when normalizing for basis weight), the inventive tissue product exhibited improving product softness. The inventive product with the additional softness is often preferred by the consumer due this improved performance.Attorney Docket No.: GP-23037-WO-PCT Table 11 Property Control Inventive Caliper (mils / 8 sheets) 104 102 Basis Weight (lbs / 3000 ft2) 28.5 27.4 Bulk (cm3 / g) 7.16 7.27 Softness (PSU) 19.2 19.9 Example 5

[0188] In Example 5, inventive tissue product was made using press felt Ex 1D of Example 1 above. Comparative tissue product was made using similar process conditions and raw materials (such as the same fiber composition, similar strength control strategies, the same forming set-up and conditions, a similar chemical utilization approach, the same pressing set-up and conditions, identical reel moisture targets, and similar converting, embossing and winding conditions) but with a control press felt. The control press felt was identical in structure to the press felt of Ex 1D, but did not include apertures as described herein.

[0189] As can be seen from the data of Table 12 below, when the inventive tissue product was targeted to achieve an equivalent softness relative to the control, the inventive product achieves a higher caliper (higher bulk when normalizing for basis weight). The inventive product with the additional thickness is often preferred by the consumer due this improved performance. Table 12 Property Control Inventive Caliper (mils / 8 sheets) 140.8 165.1 Basis Weight (lbs / 3000 ft2) 36.0 37.3 Bulk (cm3 / g) 7.63 8.64 Softness (PSU) 20.3 20.2

Claims

Attorney Docket No.: GP-23037-WO-PCT We Claim:

1. A press felt for use in a conventional wet-press papermaking machine, wherein the press felt comprises a sheet-side surface and a roll-side surface; wherein the sheet-side surface comprises a plurality of pores extending into the interior of the press felt towards the roll-side surface; wherein the press felt has a contact area of from about 40% to about 90%; wherein the plurality of pores have a pore side-wall angle from about 30° to about 55°; and wherein the plurality of pores have a pore depth from about 300 microns to about 800 microns.

2. The press felt of claim 1, wherein the plurality of pores have a pore surface diameter from about 1.0 mm to about 2.4 mm.

3. The press felt of claim 1, wherein the plurality of pores have a ratio of 90% depth diameter to surface pore diameter of from about 0.3 to about 0.

55.

4. The press felt of claim 1, wherein the press felt has a non-fused contact area of greater than about 60%.

5. The press felt of claim 1, wherein the press felt has a pore pattern offset angle from about 20° to about 40°.

6. The press felt of claim 1, wherein the press felt has a pore pattern MD distance from about 200 microns to about 1200 microns.

7. The press felt of claim 1, wherein the press felt has a pore pattern CD distance from about 500 microns to about 2000 microns.

8. The press felt of claim 1, wherein the press felt has a pore density from about 10 pore / in2to about 500 pore / in2.

9. The press felt of claim 1, wherein the plurality of pores have a sheet-side surface shape chosen from circular and oval.Attorney Docket No.: GP-23037-WO-PCT 10. The press felt of claim 1, wherein the plurality of pores have a surface aspect ratio from about 0.5 to about 2.

11. The press felt of claim 1, wherein the press felt has an air permeability of from about 10 cfm / ft2to about 40 cfm / ft2.

12. The press felt of claim 1, wherein the pores are formed by laser drilling.

13. The press felt of claim 1, wherein the press felt has a contact area of from about 40% to about 90%.

14. The press felt of claim 1, wherein the plurality of pores have a pore side-wall angle from about 35° to about 50°.

15. The press felt of claim 1, wherein the plurality of pores have a pore depth from about 400 microns to about 700 microns.

16. A method of making a paper sheet on a conventional wet-press papermaking machine comprising: dewatering a cellulosic web in the press section of a conventional wet-press papermaking machine with a press felt to form a paper sheet, wherein the press felt comprises: a sheet-side surface and a roll-side surface; wherein the sheet-side surface comprises a plurality of pores extending into the interior of the press felt towards the roll-side surface; wherein the press felt has a contact area of from about 40% to about 90%; wherein the plurality of pores have a pore side-wall angle from about 30° to about 55°; and wherein the plurality of pores have a pore depth from about 300 microns to about 800 microns.

17. The method of claim 16, further comprising forming the cellulosic web in a forming section of the papermaking machine upstream of the press section, wherein the forming section comprises a configuration chosen from twin wire and crescent.

18. The method of claim 16, further comprising drying the paper sheet on a Yankee dryer downstream of the press section.Attorney Docket No.: GP-23037-WO-PCT 19. The method of claim 18, wherein the paper sheet is adhered to the Yankee dryer with an adhesive.

20. The method of claim 18, further comprising creping the paper sheet from the Yankee dryer with a creping blade.

21. The method of claim 16, further comprising calendering the paper sheet.

22. The method of claim 16, further comprising embossing the paper sheet.

23. The method of claim 16, wherein the paper sheet is not embossed.

24. The method of claim 16, further comprising joining the paper sheet with at least one additional paper sheet to form a multi-ply paper product.

25. The method of claim 24, wherein the at least one additional paper sheet is also formed by the process of claim 16.

26. The method of claim 24, wherein the paper sheet is not embossed and wherein the at least one additional paper sheet is embossed.

27. The method of claim 16, further comprising joining the paper sheet with at least two additional paper sheets to form a multi-ply paper product.

28. The method of claim 27, wherein at least one of the at least two additional paper sheets is also formed by the process of claim 16.

29. The method of claim 27, wherein the paper sheet is not embossed and wherein at least one of the at least two additional paper sheets is embossed.

30. The method of claim 16, wherein the resultant paper sheet has a generally flat surface with raised dome regions.

31. The method of claim 20, wherein the resultant paper sheet has a generally flat surface with raised dome regions; and wherein the generally flat surface exhibits crepe bars but the raised dome regions do not exhibit crepe bars.Attorney Docket No.: GP-23037-WO-PCT 32. A paper product made by a process comprising: dewatering a cellulosic web in the press section of a conventional wet-press papermaking machine with a press felt to form a paper sheet, wherein the press felt comprises: a sheet-side surface and a roll-side surface; wherein the sheet-side surface comprises a plurality of pores extending into the interior of the press felt towards the roll-side surface; wherein the press felt has a contact area of from about 30% to about 90%; wherein the plurality of pores have a pore side-wall angle from about 30° to about 55°; and wherein the plurality of pores have a pore depth from about 300 microns to about 800 microns; and converting the paper sheet into a paper product.

33. The paper product of claim 32, wherein the product includes a generally flat surface with raised dome regions.

34. The paper product of claim 33, wherein the generally flat surface exhibits crepe bars but the raised dome regions do not exhibit crepe bars.

35. The paper product of claim 32, wherein the product is a tissue, towel, or napkin product.

36. The paper product of claim 35, wherein the product is a bath tissue.

37. The paper product of claim 35, wherein the product is a paper towel.

38. The paper product of claim 35, wherein the product is a napkin.

39. The paper product of claim 33, wherein the product is a two-ply product comprising the paper sheet and a second paper sheet.

40. The paper product of claim 39, wherein both the paper sheet and the second paper sheet are embossed.

41. The paper product of claim 39, wherein the paper sheet is not embossed and wherein the second paper sheet is embossed.Attorney Docket No.: GP-23037-WO-PCT 42. The paper product of claim 39, wherein the second paper sheet has also been made by the process of claim 32.

43. The paper product of claim 32, wherein the product is a three-ply product comprising the paper sheet, a second paper sheet, and a third paper sheet.

44. The paper product of claim 43, wherein the paper sheet is not embossed and wherein at least one of the second paper sheet and the third paper sheet is embossed.

45. The paper product of claim 43, wherein the paper sheet is embossed and wherein at least one of the second paper sheet and the third paper sheet is embossed.

46. The paper product of claim 43, wherein at least one of the second paper sheet and the third paper sheet has also been made by the process of claim 32.

47. The paper product of claim 32, wherein the product exhibits a caliper (mils / 8 sheet) at least about 5% greater than the caliper of a paper product made by an identical process, but with a conventional non-apertured press felt.

48. The paper product of claim 32, wherein the product exhibits a bulk (cm3 / g) at least about 15% greater than the bulk of a paper product made by an identical process, but with a conventional non-apertured press felt.

49. The paper product of claim 32, wherein the product exhibits a SAT capacity (g / m2) at least 20% greater than the SAT capacity of a paper product made by an identical process, but with a conventional non-apertured press felt.

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