SOFT TISSUE PRODUCED USING A STRUCTURED FABRIC AND ENERGY EFFICIENT PRESSING

Abstract

A structured rolled sanitary tissue product having at least two plies, wherein the structured rolled sanitary tissue product has a crumple resistance of less than 30 grams force, a caliper of at least 450 microns/ply, and a bulk softness (TS7) of 10 or less.

Claims

1. A structured rolled sanitary tissue product comprising at least two plies, wherein the structured rolled sanitary tissue product has a crumple resistance of less than 30 grams force, a caliper of at least 450 microns/ply, and a bulk softness (TS7) of 10 or less.

2. The structured rolled sanitary tissue product according to claim 1, wherein the structured rolled sanitary tissue product has an average peak to valley depth of at least 100 microns.

3. The structured rolled sanitary tissue product of claim 1, wherein the structured rolled sanitary tissue product has a caliper of 450 microns/2 ply to 600 microns/2 ply and is un-calendered.

4. The structured rolled sanitary tissue product of claim 1, wherein the structured rolled sanitary tissue product has a caliper of 600 microns/2 ply to 800 microns/2 ply and is uncalendered.

5. The structured rolled sanitary tissue product of claim 1, wherein the structured rolled sanitary tissue product has a caliper of 500 microns/2 ply to 700 microns/2 ply and is calendered.

6. The structured rolled sanitary tissue product of claim 1, wherein the structured rolled sanitary tissue product has a basis weight in g/m.sup.2 per 2 ply of 28 g/m.sup.2 to 39 g/m.sup.2.

7. The structured rolled sanitary tissue product of claim 1, wherein the structured rolled sanitary tissue product has a machine direction tensile strength per 2 ply of 110 N/m to 190 N/m.

8. The structured rolled sanitary tissue product of claim 1, wherein the structured rolled sanitary tissue product has a cross machine direction tensile strength per 2 ply of 35 N/m to 90 N/m.

9. The structured rolled sanitary tissue product of claim 1, wherein the structured rolled sanitary tissue product has a machine direction stretch of 4% to 30% per 2 ply.

10. The structured rolled sanitary tissue product of claim 1, wherein the structured rolled sanitary tissue product has a cross direction stretch of 4% to 20% per 2 ply.

11. The structured rolled sanitary tissue product of claim 1, wherein the structured rolled sanitary tissue product has a 2-ply cross direction wet tensile strength of 0 to 25 N/m.

12. The structured rolled sanitary tissue product of claim 1, wherein the structured rolled sanitary tissue product has a ball burst strength of 150 gf to 300 gf per 2-ply.

13. The structured rolled sanitary tissue product of claim 1, wherein the structured rolled sanitary tissue product has a lint value of 2.5 to 7.5 per 2 ply.

14. The structured rolled sanitary product of claim 1, wherein the structured rolled sanitary tissue product has a softness of 85 TSA to 100 TSA.

15. The structured rolled sanitary product of claim 1, wherein the structured rolled sanitary tissue product has a bulk softness (TS7) of from 8 to 10.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0106] The features and advantages of exemplary embodiments of the present invention will be more fully understood with reference to the following, detailed description when taken in conjunction with the accompanying figures, wherein:

[0107] FIG. 1 is a cross-sectional view of a multi-layer tissue according to an exemplary embodiment of the present invention;

[0108] FIG. 2 is a block diagram of a system for manufacturing tissue according to an exemplary embodiment of the present invention;

[0109] FIG. 3 is a block diagram of a system for manufacturing tissue according to another exemplary embodiment of the present invention; and

[0110] FIGS. 4A and 4B is a chart providing a lint testing procedure useable with exemplary embodiments of the present invention.

DETAILED DESCRIPTION

[0111] An object of the present invention is to provide a paper manufacturing method that utilizes a structured fabric in conjunction with a belt press which can be used in the production of sanitary tissue and facial products, with unique and quantifiable quality and softness attributes.

[0112] In at least one exemplary embodiment, the web is a multilayered structure with particular fibers and chemistry added in each layer to maximize quality attributes including web softness. In at least one exemplary embodiment, pulp mixes for each tissue layer are prepared individually.

[0113] For the purposes of describing the present invention, the terms “structured tissue product” or “structured paper product” refer to a tissue or other paper product produced using a structured or imprinting fabric.

[0114] The present disclosure is related to U.S. patent application Ser. No. 13/837,685 (now U.S. Pat. No. 8,968,517), filed Mar. 15, 2014, the contents of which are incorporated herein by reference in their entirety.

[0115] A new process/method and paper machine system for producing tissue has been developed by Voith GmbH, of Heidenheim, Germany, and is being marketed under the name ATMOS (Advanced Tissue Molding System). The process/method and paper machine system has several patented variations, but all involve the use of a structured fabric in conjunction with a belt press. The major steps of the ATMOS process and its variations are stock preparation, forming, imprinting, pressing (using a belt press), creping, calendering (optional), and reeling the web.

[0116] The stock preparation step is the same as a conventional or TAD machine would utilize. The purpose is to prepare the proper recipe of fibers, chemical polymers, and additives that are necessary for the grade of tissue being produced, and diluting this slurry to allow for proper web formation when deposited out of the machine headbox (single, double, or triple layered) to the forming surface. The forming process can utilize a twin wire former (as described in U.S. Pat. No. 7,744,726), a Crescent Former with a suction Forming Roll (as described in U.S. Pat. No. 6,821,391), or preferably a Crescent Former (as described in U.S. Pat. No. 7,387,706). The preferred former is provided a slurry from the headbox to a nip formed by a structured fabric (inner position/in contact with the forming roll) and forming fabric (outer position). The fibers from the slurry are predominately collected in the valleys (or pockets, pillows) of the structured fabric and the web is dewatered through the forming fabric. This method for forming the web results in a unique bulk structure and surface topography as described in U.S. Pat. No. 7,387,706 (see, in particular, FIG. 1 through FIG. 11). The fabrics separate after the forming roll with the web staying in contact with the structured fabric. At this stage, the web is already imprinted by the structured fabric, but utilization of a vacuum box on the inside of the structured fabric can facilitate further fiber penetration into the structured fabric and a deeper imprint.

[0117] The web is now transported on the structured fabric to a belt press. The belt press can have multiple configurations. The first patented belt press configurations used in conjunction with a structured fabric can be viewed in U.S. Pat. No. 7,351,307 (FIG. 13), where the web is pressed against a dewatering fabric across a vacuum roll by an extended nip belt press. The press dewaters the web while protecting the areas of the sheet within the structured fabric valleys from compaction. Moisture is pressed out of the web, through the dewatering fabric, and into the vacuum roll. The press belt is permeable and allows for air to pass through the belt, web, and dewatering fabric, into the vacuum roll enhancing the moisture removal. Since both the belt and dewatering fabric are permeable, a hot air hood can be placed inside of the belt press to further enhance moisture removal as shown in FIG. 14 of U.S. Pat. No. 7,351,307. Alternately, the belt press can have a pressing device arranged within the belt which includes several press shoes, with individual actuators to control cross direction moisture profile, (see FIG. 28 of U.S. Pat. No. 7,951,269 or 8,118,979 or FIG. 20 of U.S. Pat. No. 8,440,055) or a press roll (see FIG. 29 of U.S. Pat. No. 7,951,269 or 8,118,979 or FIG. 21 of U.S. Pat. No. 8,440,055). The preferred arrangement of the belt press has the web pressed against a permeable dewatering fabric across a vacuum roll by a permeable extended nip belt press. Inside the belt press is a hot air hood that includes a steam shower to enhance moisture removal. The hot air hood apparatus over the belt press can be made more energy efficient by reusing a portion of heated exhaust air from the Yankee air cap or recirculating a portion of the exhaust air from the hot air apparatus itself (see U.S. Pat. No. 8,196,314). Further embodiments of the drying system composed of the hot air apparatus and steam shower in the belt press section are described in U.S. Pat. Nos. 8,402,673, 8,435,384 and 8,544,184.

[0118] After the belt press is a second press to nip the web between the structured fabric and dewatering felt by one hard and one soft roll. The press roll under the dewatering fabric can be supplied with vacuum to further assist water removal. This preferred belt press arrangement is described in U.S. Pat. Nos. 8,382,956, and 8,580,083, with FIG. 1 showing the arrangement. Rather than sending the web through a second press after the belt press, the web can travel through a boost dryer (FIG. 15 of U.S. Pat. Nos. 7,387,706 and 7,351,307), a high pressure through air dryer (FIG. 16 of U.S. Pat. Nos. 7,387,706 and 7,351,307), a two pass high pressure through air dryer (FIG. 17 of U.S. Pat. Nos. 7,387,706 and 7,351,307) or a vacuum box with hot air supply hood (FIG. 2 of U.S. Pat. No. 7,476,293). U.S. Pat. Nos. 7,510,631, 7,686,923, 7,931,781 8,075,739, and 8,092,652 further describe methods and systems for using a belt press and structured fabric to make tissue products each having variations in fabric designs, nip pressures, dwell times, etc. and are mentioned here for reference. A wire turning roll can be also be utilized with vacuum before the sheet is transferred to a steam heated cylinder via a pressure roll nip (see FIG. 2a of U.S. Pat. No. 7,476,293).

[0119] The sheet is now transferred to a steam heated cylinder via a press element. The press element can be a through drilled (bored) pressure roll (FIG. 8 of U.S. Pat. No. 8,303,773), a through drilled (bored) and blind drilled (blind bored) pressure roll (FIG. 9 of U.S. Pat. No. 8,303,773), or a shoe press (U.S. Pat. No. 7,905,989). After the web leaves this press element to the steam heated cylinder, the % solids are in the range of 40-50% solids. The steam heated cylinder is coated with chemistry to aid in sticking the sheet to the cylinder at the press element nip and also aid in removal of the sheet at the doctor blade. The sheet is dried to up to 99% solids by the steam heated cylinder and installed hot air impingement hood over the cylinder. This drying process, the coating of the cylinder with chemistry, and the removal of the web with doctoring is explained in U.S. Pat. Nos. 7,582,187 and 7,905,989. The doctoring of the sheet off the Yankee, creping, is similar to that of TAD with only the knuckle sections of the web being creped. Thus the dominant surface topography is generated by the structured fabric, with the creping process having a much smaller effect on overall softness as compared to conventional dry crepe.

[0120] The web is now calendered (optional) slit, and reeled and ready for the converting process. These steps are described in U.S. Pat. No. 7,691,230.

[0121] The preferred ATMOS process has the following steps: Forming the web using a Crescent Former between an outer forming fabric and inner structured fabric, imprinting the pattern of the structured fabric into the web during forming with the aid of a vacuum box on the inside of the structured fabric after fabric separation, pressing (and dewatering) the web against a dewatering fabric across a vacuum roll using an extended nip belt press belt, using a hot air impingement hood with a steam shower inside the belt press to aid in moisture removal, reuse of exhaust air from the Yankee hot air hood as a percentage of makeup air for the belt press hot air hood for energy savings, use of a second press nip between a hard and soft roll with a vacuum box installed in the roll under the dewatering fabric for further dewatering, transferring the sheet to a steam heated cylinder (Yankee cylinder) using a blind and through drilled press roll (for further dewatering), drying the sheet on the steam cylinder with the aid of a hot air impingement hood over the cylinder, creping, calendering, slitting, and reeling the web.

[0122] The benefits of this preferred process are numerous. First, the installed capital cost is only slightly above that of a conventional crescent forming tissue machine and thus nearly half the cost of a TAD machine. The energy costs are equal to that of a conventional tissue machine which are half that of a TAD machine. The thickness of the web is nearly equal to that of a TAD product and up to 100% thicker than a conventional tissue web. The quality of the products produced in terms of softness and strength are comparable to TAD and greater than that produced from a conventional tissue machine. The softness attributes of smoothness and bulk structure are unique and different than that of TAD and Conventional tissue products and are not only a result of the unique forming systems (a high percentage of the fibers collected in the valleys of the structured fabric and are protected from compaction through the process) and dewatering systems (extended nip belted press allows for low nip intensity and less web compaction) of the ATMOS process itself, but also the controllable parameters of the process (fiber selection, chemistry selection, degree of refining, structured fabric utilized, Yankee coating chemistry, creping pocket angle, creping moisture, and amount of calendering).

[0123] The ATMOS manufacturing technique is often described as a hybrid technology because it utilizes a structured fabric like the TAD process, but also utilizes energy efficient means to dewater the sheet like the Conventional Dry Crepe process. Other manufacturing techniques which employ the use of a structured fabric along with an energy efficient dewatering process are the ETAD process and NTT process. The ETAD process and products are disclosed in U.S. Pat. Nos. 7,339,378, 7,442,278, and 7,494,563. This process can utilize any type of former such as a Twin Wire Former or Crescent Former. After formation and initial drainage in the forming section, the web is transferred to a press fabric where it is conveyed across a suction vacuum roll for water removal, increasing web solids up to 25%. Then the web travels into a nip formed by a shoe press and backing/transfer roll for further water removal, increasing web solids up to 50%. At this nip, the web is transferred onto the transfer roll and then onto a structured fabric via a nip formed by the transfer roll and a creping roll. At this transfer point, speed differential can be utilized to facilitate fiber penetration into the structured fabric and build web caliper. The web then travels across a molding box to further enhance fiber penetration if needed. The web is then transferred to a Yankee dryer where it can be optionally dried with a hot air impingement hood, creped, calendared, and reeled. The NTT process and products are disclosed in PCT International Patent Application Publication WO 200906709A1. The process has several embodiments, but the key step is the pressing of the web in a nip formed between a structured fabric and press felt. The web contacting surface of the structured fabric is a non-woven material with a three dimensional structured surface comprised of elevation and depressions of a predetermined size and depth. As the web is passed through this nip, the web is formed into the depression of the structured fabric since the press fabric is flexible and will reach down into all of the depressions during the pressing process. When the felt reaches the bottom of the depression, hydraulic force is built up which forces water from the web and into the press felt. To limit compaction of the web, the press rolls will have a long nip width which can be accomplished if one of the rolls is a shoe press. After pressing, the web travels with the structured fabric to a nip with the Yankee dryer, where the sheet is optionally dried with a hot air impingement hood, creped, calendared, and reeled.

[0124] FIG. 1 shows a three layer tissue, generally designated by reference number 1, according to an exemplary embodiment of the present invention. The tissue 1 has external layers 2 and 4 as well as an internal, core layer 3. External layer 2 is composed primarily of hardwood fibers 20 whereas external layer 4 and core layer 3 are composed of a combination of hardwood fibers 20 and softwood fibers 21. The internal core layer 3 includes an ionic surfactant functioning as a debonder 5 and a non-ionic surfactant functioning as a softener 6. As explained in further detail below, external layers 2 and 4 also include non-ionic surfactant that migrated from the internal core layer 3 during formation of the tissue 1. External layer 2 further includes a dry strength additive 7. External layer 4 further includes both a dry strength additive 7 and a temporary wet strength additive 8.

[0125] Pulp mixes for exterior layers of the tissue are prepared with a blend of primarily hardwood fibers. For example, the pulp mix for at least one exterior layer is a blend containing about 70 percent or greater hardwood fibers relative to the total percentage of fibers that make up the blend. As a further example, the pulp mix for at least one exterior layer is a blend containing about 90-100 percent hardwood fibers relative to the total percentage of fibers that make up the blend.

[0126] Pulp mixes for the interior layer of the tissue are prepared with a significant percentage of softwood fibers. For example, the pulp mix for the interior layer is a blend containing about 40 percent or greater softwood fibers relative to the total percentage of fibers that make up the blend. A percentage of the softwood fibers can be replaced with cannabis to limit fiber costs.

[0127] As known in the art, pulp mixes are subjected to a dilution stage in which water is added to the mixes so as to form a slurry. After the dilution stage, but prior to reaching the headbox, each of the pulp mixes are dewatered to obtain a thick stock of about 99.5% water. In an exemplary embodiment of the invention, wet end additives are introduced into the thick stock pulp mixes of at least the interior layer. In an exemplary embodiment, a non-ionic surfactant and an ionic surfactant are added to the pulp mix for the interior layer. Suitable non-ionic surfactants have a hydrophilic-lipophilic balance of less than 10 and preferably less than or equal to 8.5. An exemplary non-ionic surfactant is an ethoxylated vegetable oil or a combination of two or more ethoxylated vegetable oils. Other exemplary non-ionic surfactants include ethylene oxide, propylene oxide adducts of fatty alcohols, alkylglycoside esters, and alkylethoxylated esters.

[0128] Suitable ionic surfactants include but are not limited to quaternary amines and cationic phospholipids. An exemplary ionic surfactant is 1,2-di(heptadecyl)-3-methyl-4,5-dihydroimidazol-3-ium methyl sulfate. Other exemplary ionic surfactants include (2-hydroxyethyl)methylbis[2-[(1-oxooctadecyl)oxy]ethyl]ammonium methyl sulfate, fatty dialkyl amine quaternary salts, mono fatty alkyl tertiary amine salts, unsaturated alkyl amine salts, linear alkyl sulfonates, alkyl-benzene sulfonates and trimethyl-3-[(1-oxooctadecyl)amino]propylammonium methyl sulfate.

[0129] In an exemplary embodiment, the ionic surfactant may function as a debonder while the non-ionic surfactant functions as a softener. Typically, the debonder operates by breaking bonds between fibers to provide flexibility, however an unwanted side effect is that the overall strength of the tissue can be reduced by excessive exposure to debonder. Typical debonders are quaternary amine compounds such as trimethyl cocoammonium chloride, trimethyloleylammonium chloride, dimethydi(hydrogenated-tallow)ammonium chloride and trimethylstearylammonium chloride.

[0130] After being added to the interior layer, the non-ionic surfactant (functioning as a softener) migrates through the other layers of the tissue while the ionic surfactant (functioning as a debonder) stays relatively fixed within the interior layer. Since the debonder remains substantially within the interior layer of the tissue, softer hardwood fibers (that may have lacked sufficient tensile strength if treated with a debonder) can be used for the exterior layers. Further, because only the interior of the tissue is treated, less debonder is required as compared to when the whole tissue is treated with debonder.

[0131] In an exemplary embodiment, the ratio of ionic surfactant to non-ionic surfactant added to the pulp mix for the interior layer of the tissue is between 1:4 and 1:90 parts by weight and preferably about 1:8 parts by weight. In particular, when the ionic surfactant is a quaternary amine debonder, reducing the concentration relative to the amount of non-ionic surfactant can lead to an improved tissue. Excess debonder, particularly when introduced as a wet end additive, can weaken the tissue, while an insufficient amount of debonder may not provide the tissue with sufficient flexibility. Because of the migration of the non-ionic surfactant to the exterior layers of the tissue, the ratio of ionic surfactant to non-ionic surfactant in the core layer may be significantly lower in the actual tissue compared to the pulp mix.

[0132] In an exemplary embodiment, a dry strength additive is added to the thick stock mix for at least one of the exterior layers. The dry strength additive may be, for example, amphoteric starch, added in a range of about 1 to 40 kg/ton. In another exemplary embodiment, a wet strength additive is added to the thick stock mix for at least one of the exterior layers. The wet strength additive may be, for example, glyoxalated polyacrylamide, commonly known as GPAM, added in a range of about 0.25 to 5 kg/ton. In a further exemplary embodiment, both a dry strength additive, preferably amphoteric starch and a wet strength additive, preferably GPAM are added to one of the exterior layers. Without being bound by theory, it is believed that the combination of both amphoteric starch and GPAM in a single layer when added as wet end additives provides a synergistic effect with regard to strength of the finished tissue. Other exemplary temporary wet-strength agents include aldehyde functionalized cationic starch, aldehyde functionalized polyacrylamides, acrolein co-polymers and cis-hydroxyl polysaccharide (guar gum and locust bean gum) used in combination with any of the above mentioned compounds.

[0133] In addition to amphoteric starch, suitable dry strength additives may include but are not limited to glyoxalated polyacrylamide, cationic starch, carboxy methyl cellulose, guar gum, locust bean gum, cationic polyacrylamide, polyvinyl alcohol, anionic polyacrylamide or a combination thereof.

[0134] FIG. 2 is a diagram of a system for manufacturing tissue, generally designated by reference number 100, according to an exemplary embodiment of the present invention. The system includes a first exterior layer fan pump 125, a core layer fan pump 126, and a second exterior layer fan pump 127. The fan pumps move the dilute slurry of fiber and chemicals to a triple layer headbox 101 which deposits the slurry into a nip formed by a forming roll 102, an outer forming wire 103 and structured fabric 124. The slurry is drained through the outer wire 103 to form a web. The web properties at this point are a result of the selection and layering of fibers and chemistry, the formation of the web which influences strength development, and the topographical pattern formed into the sheet by the structured fabric. A smooth surface topography is realized by using low coarseness hardwood fibers in the first exterior layer with no or minimal refining, and a structured fabric with a fine weave pattern. The web has the inclusion of starch for lint control and the inclusion of GPAM to impart a degree of temporary wet strength. The strength of the web is maintained at a level acceptable for use, but low enough to impart a degree of web flexibility and drape. The strength is maintained by using minimal refining of the softwood and cannabis fibers contained in the interior and second exterior layers along with inclusion of the starch polymer which improves the web strength in the Z-direction. Inclusion of an ionic surfactant in the interior layer to debond the fibers also improves sheet flexibility.

[0135] After formation, the fabrics separate after the forming roll 102 with the web following the structured fabric 124. A vacuum box 104 is utilized on the inside of the structured fabric to assist with pulling the fibers deeper into the fabric to improve bulk structure and pattern definition. The web is conveyed on the structured fabric 124 to a belt press made up of a permeable belt 107, a permeable dewatering fabric 112, a hot air impingement hood 109 within the belt press containing a steam shower 108, and a vacuum roll 110. The web is heated by the steam and hot air of the hot air impingement hood 109 to lower the viscosity of the water within the web which is being pressed by the belt press to move the water into the dewatering fabric 112 and into the vacuum roll 110. The vacuum roll 110 holds a significant portion of the water within the through and blind drilled holes in the roll cover (rubber or polyurethane) until vacuum is broken at the exit of the vacuum box, upon which time the water is deposited into a save-all pan 111. The air flow through web, provided by the hot air hood and vacuum of the vacuum roll, also facilitates water removal as moisture is trapped in the air stream. At this stage, the web properties are influenced by the structured fabric design and low intensity pressing. The bulk softness of the web is preserved due to the low intensity nip of the belt press which will not compress the web portions within the valleys of the structured fabric. The smoothness of the web is influenced by the unique surface topography imprinted by the structured fabric which is dependent on the parameters of weave pattern, mesh, count, weft and warp monofilament diameter, caliper and % of the fabric that is knuckle verses valley.

[0136] The web now travels through a second press comprised of a hard roll 114 and soft or press roll 113. The press roll 113 inside the dewatering fabric 112 contains a vacuum box to facilitate water removal. The web now travels upon the structured fabric 124 to a wire turning roll (not shown) with an optional vacuum box to a nip between a blind and through drilled polyurethane or rubber covered press roll 115 and steam heated pressure cylinder 116. The web solids are up to 50% solids as the web is transferred to the steam heated cylinder 116 that is coated with chemicals that improve web adhesion to the dryer, improve heat transfer through the web, and assist in web removal at the creping doctor 120. The chemicals are constantly being applied at this point using a sprayboom 118, while excess is being removed using a cleaning doctor blade 119. The web is dried by the steam heated cylinder 116 along with an installed hot air impingement hood 117 to a solids content of 97.5%. The web is removed from the steam heated cylinder using a ceramic doctor blade with a pocket angle of 90 degrees at the creping doctor 120. At this stage, the web properties are influenced by the creping action occurring at the creping doctor. A larger creping pocket angle will increase the frequency and fineness of the crepe bars imparted to the web's first exterior surface, which improves surface smoothness. A ceramic doctor blade is preferred, which allows for a fine crepe bar pattern to be imparted to the web for a long duration of time compared to a steel or bimetal blade. Surface smoothness is also increased as the non-ionic surfactant in the core layer migrates to the first and second exterior layer as the heat from the Yankee cylinder and hot air impingement hood draw the surfactant to the surfaces of the web.

[0137] The creping action imparted at the blade also improves web flexibility and is a result of the force imparted to the sheet at the crepe blade and is improved as the web adherence to the dryer is increased. The creping force is primarily influenced by the chemistry applied to the steam heated cylinder, the % web contact with the cylinder surface which is a result of the knuckle pattern of the structured fabric, and the percent web solids upon creping.

[0138] The web now optionally travels through a set of calenders 121 running 15% slower than the steam heated cylinder 116. The action of calendering improves sheet smoothness but results in lower bulk softness by reducing overall web thickness. The amount of calendering can be influenced by the attributes needed in the finished product. For example; a low sheet count, 2-ply, rolled sanitary tissue product will need less calendering than the same roll of 2-ply sanitary product at a higher sheet count and the same roll diameter and firmness. That is, the thickness of the web may need to be reduced using calendering to allow for more sheets to fit on a roll of sanitary tissue given limitations to roll diameter and firmness. After calendering, the web is reeled using a reel drum 122 into a parent roll 123.

[0139] The parent roll can be converted into 1 or 2-ply rolled sanitary products or 1, 2, or 3 ply folded facial tissue products. In addition to the use of wet end additives, the web may also be treated with topical or surface deposited additives in the converting process or on the paper machine after the creping blade. Examples of surface deposited additives include softeners for increasing fiber softness and skin lotions. Examples of topical softeners include but are not limited to quaternary ammonium compounds, including, but not limited to, the dialkyldimethylammonium salts (e.g. ditallowdimethylammonium chloride, ditallowdimethylammonium methyl sulfate, di(hydrogenated tallow)dimethyl ammonium chloride, etc.). Another class of chemical softening agents include the well-known organo-reactive polydimethyl siloxane ingredients, including amino functional polydimethyl siloxane, zinc stearate, aluminum stearate, sodium stearate, calcium stearate, magnesium stearate, spermaceti, and steryl oil.

[0140] FIG. 3 is a diagram of a system for manufacturing tissue, generally designated by reference number 200, according to an exemplary embodiment of the present invention. The system includes a first exterior layer fan pump 225, a core layer fan pump 226, and a second exterior layer fan pump 227. The fan pumps 225, 226, 227 move the dilute slurry of fiber and chemicals to a triple layer headbox 201 which deposits the slurry into a nip formed by a forming roll 202, an outer forming wire 203, and an inner forming wire 205. The slurry is drained through the outer wire 203 to form a web. The web properties at this point are a result of the selection and layering of fibers and chemistry along with the formation of the web which influences strength development. A smooth surface topography is realized by using low coarseness hardwood fibers in the first exterior layer with no or minimal refining, the inclusion of starch for lint control, and the inclusion of GPAM to impart a degree of temporary wet strength. The strength of the web is maintained at a level acceptable for use, but low enough to impart a degree of web flexibility and drape. The strength is being maintained by using minimal refining of the softwood and cannabis fibers contained in the interior and second exterior layers along with inclusion of the starch polymer which improves the web strength in the Z-direction. Inclusion of an ionic surfactant in the interior layer to debond the fibers also improves sheet flexibility.

[0141] A vacuum box 204 is used to assist in web transfer to the inner wire 205 which conveys the sheet to a structured imprinting fabric 224. A speed differential between the inner wire 205 and structured fabric 224 is utilized to increase web caliper as the web is transferred to the structured fabric 224. A vacuum box or multiple vacuum boxes 206 are used to assist in transfer and imprinting the web using the structured fabric 224 which contains a unique structure dictated by the attributes of fabric. The web portions contacting the valleys of the structure fabric are pulled into these valleys with the assistance of the speed differential and vacuum.

[0142] The web is conveyed on the structured fabric 224 to a belt press made up of a permeable belt 207, a permeable dewatering fabric 212, a hot air impingement hood 209 within the belt press containing a steam shower 208, and a vacuum roll 210. The web is heated by the steam and hot air of the hot air impingement hood 209 to lower the viscosity of the water within the web which is being pressed by the belt press to move the water into the dewatering fabric and into the vacuum roll 210. The vacuum roll 210 holds a significant portion of the water within the through and blind drilled holes in the roll cover (rubber or polyurethane) until vacuum is broken at the exit of the vacuum box, upon which time the water is deposited into a save-all pan 211. The air flow through web, provided by the hot air hood 209 and vacuum of the vacuum roll 210, also facilitates water removal as moisture is trapped in the air stream. At this stage, the web properties are influenced by the structured fabric design and low intensity pressing. The bulk softness of the web is preserved due to the low intensity nip of the belt press which will not compress the web portions within the valleys of the structured fabric 212. The smoothness of the web is influenced by the unique surface topography imprinted by the structured fabric 212 which is dependent on the parameters of weave pattern, mesh, count, weft and warp monofilament diameter, caliper and % of the fabric that is knuckle verses valley.

[0143] The web now travels through a second press comprised of a hard roll and soft roll. The press roll 213 inside the dewatering fabric 212 contains a vacuum box to facilitate water removal. The web now travels upon the structured fabric 212 to a wire turning roll 214 with an optional vacuum box to a nip between a blind and through drilled polyurethane or rubber covered press roll 215 and steam heated pressure cylinder 216. The web solids are up to 50% solids as the web is transferred to the steam heated cylinder 216 that is coated with chemicals that improve web adhesion to the dryer, improve heat transfer through the web, and assist in web removal at the creping doctor 220. The chemicals are constantly being applied using a sprayboom 218, while excess is being removed using a cleaning doctor blade 219. The web is dried by the steam heated cylinder 216 along with an installed hot air impingement hood 217 to a solids content of 97.5%. The web is removed from the steam heated cylinder 216 using a ceramic doctor blade 220 with a pocket angle of 90 degrees at the creping doctor. At this stage, the web properties are influenced by the creping action occurring at the creping doctor. A larger creping pocket angle will increase the frequency and fineness of the crepe bars imparted to the web's first exterior surface, which improves surface smoothness. The use of a ceramic doctor blade will also allow for a fine crepe bar pattern to be imparted to the web for a long duration of time compared to a steel or bimetal blade and is recommended. Surface smoothness is also increased as the non-ionic surfactant in the core layer migrates to the first and second exterior layer as the heat from the Yankee cylinder 216 and hot air impingement hood 217 draw the surfactant to the surfaces of the web.

[0144] The creping action imparted at the blade also improves web flexibility and is a result of the force imparted to the sheet at the crepe blade and is improved as the web adherence to the dryer is increased. The creping force is primarily influenced by the chemistry applied to the steam heated cylinder, the % web contact with the cylinder surface which is a result of the knuckle pattern of the structured fabric, and the percent web solids upon creping.

[0145] The web now optionally travels through a set of calendars 221 running, for example, 15% slower than the steam heated cylinder. The action of calendaring improves sheet smoothness but results in lower bulk softness by reducing overall web thickness. The amount of calendaring can be influenced by the attributes needed in the finished product. For example; a low sheet count, 2-ply, rolled sanitary tissue product will need less calendaring than the same roll of 2-ply sanitary product at a higher sheet count and the same roll diameter and firmness. Meaning; the thickness of the web may need to be reduced using calendaring to allow for more sheets to fit on a roll of sanitary tissue given limitations to roll diameter and firmness. After calendaring, the web is reeled using a reel drum 222 into a parent roll 223.

[0146] The parent roll 223 can be converted into 1 or 2-ply rolled sanitary products or 1, 2, or 3 ply folded facial tissue products. In addition to the use of wet end additives, the web may also be treated with topical or surface deposited additives in the converting process or on the paper machine after the creping blade. Examples of surface deposited additives include softeners for increasing fiber softness and skin lotions. Examples of topical softeners include but are not limited to quaternary ammonium compounds, including, but not limited to, the dialkyldimethylammonium salts (e.g. ditallowdimethylammonium chloride, ditallowdimethylammonium methyl sulfate, di(hydrogenated tallow)dimethyl ammonium chloride, etc.). Another class of chemical softening agents include the well-known organo-reactive polydimethyl siloxane ingredients, including amino functional polydimethyl siloxane, zinc stearate, aluminum stearate, sodium stearate, calcium stearate, magnesium stearate, spermaceti, and steryl oil.

[0147] The below discussed values for softness (i.e., hand feel (HF)), ball burst, caliper, tensile strength, stretch, crumple resistance, peak to valley distance, and basis weight of the inventive tissue were determined using the following test procedures:

[0148] Softness Testing

[0149] Softness of a 2-ply tissue web was determined using a Tissue Softness Analyzer (TSA), available from EMTECH Electronic GmbH of Leipzig, Germany. A punch was used to cut out three 100 cm.sup.2 round samples from the web. One of the samples was loaded into the TSA, clamped into place, and the TPII algorithm was selected from the list of available softness testing algorithms displayed by the TSA. After inputting parameters for the sample, the TSA measurement program was run. The test process was repeated for the remaining samples and the results for all the samples were averaged.

[0150] Ball Burst Testing

[0151] Ball Burst of a 2-ply tissue web was determined using a Tissue Softness Analyzer (TSA), available from EMTECH Electronic GmbH of Leipzig, Germany using A ball burst head and holder. A punch was used to cut out five 100 cm.sup.2 round samples from the web. One of the samples was loaded into the TSA, with the embossed surface facing down, over the holder and held into place using the ring. The ball burst algorithm was selected from the list of available softness testing algorithms displayed by the TSA. The ball burst head was then pushed by the EMTECH through the sample until the web ruptured and the grams force required for the rupture to occur was calculated. The test process was repeated for the remaining samples and the results for all the samples were averaged.

[0152] Crumple Testing

[0153] Crumple of a 2-ply tissue web was determined using a Tissue Softness Analyzer (TSA), available from EMTECH Electronic GmbH of Leipzig, Germany, using the crumple fixture (33 mm) and base. A punch was used to cut out five 100 cm.sup.2 round samples from the web. One of the samples was loaded into the crumple base, clamped into place, and the crumple algorithm was selected from the list of available testing algorithms displayed by the TSA. After inputting parameters for the sample, the crumple measurement program was run. The test process was repeated for the remaining samples and the results for all the samples were averaged. Crumple force is a good measure of the flexibility or drape of the product.

[0154] Stretch & MD, CD, and Wet CD Tensile Strength Testing

[0155] An Instron 3343 tensile tester, manufactured by Instron of Norwood, Mass., with a 100N load cell and 25.4 mm rubber coated jaw faces was used for tensile strength measurement. Prior to measurement, the Instron 3343 tensile tester was calibrated. After calibration, 8 strips of 2-ply product, each one inch by four inches, were provided as samples for each test. For testing MD tensile strength, the strips are cut in the MD direction and for testing CD tensile strength the strips are cute in the CD direction. One of the sample strips was placed in between the upper jaw faces and clamp, and then between the lower jaw faces and clamp with a gap of 2 inches between the clamps. A test was run on the sample strip to obtain tensile and stretch. The test procedure was repeated until all the samples were tested. The values obtained for the eight sample strips were averaged to determine the tensile strength of the tissue. When testing CD wet tensile, the strips are placed in an oven at 105 deg Celsius for 5 minutes and saturated with 75 microliters of deionized water immediately prior to pulling the sample.

[0156] Lint Testing

[0157] The table shown in FIG. 4 describes a lint testing procedure using a Sutherland® 2000™ Rub Tester, manufactured by Danilee Co., of San Antonio, Tex., USA.

[0158] Basis Weight

[0159] Using a dye and press, six 76.2 mm by 76.2 mm square samples were cut from a 2-ply product being careful to avoid any web perforations. The samples were placed in an oven at 105 deg C. for 5 minutes before being weighed on an analytical balance to the fourth decimal point. The weight of the sample in grams is divided by (0.0762 m).sup.2 to determine the basis weight in grams/m.sup.2.

[0160] Caliper Testing

[0161] A Thwing-Albert ProGage 100 Thickness Tester, manufactured by Thwing Albert of West Berlin, N.J., USA, was used for the caliper test. Eight 100 mm×100 mm square samples were cut from a 2-ply product. The samples were then tested individually and the results were averaged to obtain a caliper result for the base sheet.

[0162] Peak Valley

[0163] Peak/Valley of a 2-ply tissue web was determined using a Keyence VHX-1000E microscope available from Keyence Corporation of America, Elmwood Park, N.J., USA, with the following set-up; VHX-1100 camera unit, VHX-S50 free-angle motorized stage, VHX-H3M application software, OP-66871 bayonnet, VH-Z20W lens 20×-200×, and VH—K.sub.2O adjustable illumination adapter. An undisturbed sample was taken from the roll and placed on the stage. Using the camera, an un-embossed portion of the web was centered in order to only view the imprinted structured fabric pattern. Using “Depth up/3-D” an image was taken at 100× and measured using the software, across the highest point to the lowest point, this was repeated 5 times moving the stage to various areas on the sheet.

Example 1

[0164] A rolled 2-ply sanitary tissue product with 425 sheets, a roll firmness of 6.5, a roll diameter of 133 mm, with sheets a length of 4.25 inches and width of 4.0 inches, was produced using a manufacturing method that utilizes a structured fabric and belt press. The 2-ply tissue product further has the following product attributes: Basis Weight 30 g/m.sup.2, Caliper 0.330 mm, MD tensile strength of 160 N/m, CD tensile strength of 65 N/m, a ball burst of 210 grams force, a crumple resistance of 23.9 grams force, a peak to valley depth of 51.3 microns, a lint value of 5.5, an MD stretch of 14%, a CD stretch of 6%, and a CD wet tensile strength of 14 N/m.

[0165] The tissue web was multilayered with the fiber and chemistry of each layer selected and prepared individually to maximize product quality attributes of softness and strength. The first exterior layer, which was the layer that contacted the Yankee dryer, was prepared using 100% eucalyptus with 1.0 kg/ton of the amphoteric starch Redibond 2038 (Corn Products, 10 Finderne Avenue, Bridgewater, N.J., USA) (for lint control) and 1.0 kg/ton of the glyoxylated polyacrylamide Hercobond 1194 (Ashland, Wilmington Del., USA) (for strength when wet). The interior layer was composed of 10% pre-refined and bleached cannabis fibers, 30% northern bleached softwood kraft fibers, 60% eucalyptus fibers, and 1.0 kg/ton of T526, a softener/debonder supplied by EKA (EKA Chemicals Inc., Marietta, Ga., USA). The second exterior layer was composed of 10% pre-refined and bleached cannabis fibers, 20% northern bleached softwood kraft fibers, 70% eucalyptus fibers and 1.0 kg/ton of Redibond 2038 (to limit refining and impart Z-direction strength). The eucalyptus in each layer was lightly refined at 15 kwh/ton to help facilitate better web bonding to the Yankee dryer, while the softwood was refined at 30 kwh/ton to impart the necessary tensile strength.

[0166] The fiber and chemicals mixtures were diluted to a solids of 0.5% consistency and fed to separate fan pumps which delivered the slurry to a triple layered headbox. The headbox pH was controlled to 7.0 by addition of a caustic to the thick stock before the fan pumps. The headbox deposited the slurry to a nip formed by a forming roll, an outer forming wire, and structured fabric. The slurry was drained through the outer wire, which is a KT194-P design supplied by Asten Johnson (Charleston, S.C., USA), to aid with drainage, fiber support, and web formation. When the fabrics separated, the web followed the structured fabric which contained a vacuum box inside the fabric run to facilitate with fiber penetration into the structured fabric to enhance bulk softness and web imprinting.

[0167] The structured fabric was a P10 design supplied by Voith and was a 5 shed design with a warp pick sequence of 1,3,5,2,4, a 51 by 36 yarn/in Mesh and Count, a 0.30 mm warp monofilament, a 0.35 mm weft monofilament, a 0.79 mm caliper, with a 610 cfm and a knuckle surface that was sanded to impart 27% contact area with the Yankee dryer. The web was transferred to a belt press assembly made up of a permeable belt which pressed the non-web contacting surface of the structured fabric while the web was nipped between a permeable dewatering fabric and a vacuum roll. The vacuum roll was through and blind drilled and supplied with 0.5 bar vacuum while the belt press was supplying 30 kN/meter loading and was of the BW2 design supplied by Voith. A hot air impingement hood installed in the belt press was heating the water in the web using a steam shower at 0.4 bar pressure and hot air at a temperature of 150 deg C. The heated water within the web was pressed into the dewatering fabric which was of the AX2 design supplied by Voith. A significant portion of the water that was pressed into the dewatering fabric was pulled into the vacuum roll blind and bored roll cover and then deposited into the save-all pan after the vacuum was broken at the outgoing nip between the belt press and vacuum roll. Water was also pulled through the vacuum roll and into a separator as the air stream was laden with moisture.

[0168] The web then traveled to a second press section and was nipped between the dewatering fabric and structured fabric using a hard and soft roll. The roll under the dewatering fabric was supplied with 0.5 bar vacuum to assist further with water removal. The web then traveled with the structured fabric to the suction pressure roll, while the dewatering fabric was conditioned using showers and a uhle box to remove contaminants and excess water. The web was nipped up to 50 pli of force at the pressure roll nip while 0.5 bar vacuum was applied to further remove water.

[0169] The web was at that point 50% solids and was transferred to the Yankee dryer that was coated with the Magnos coating package supplied by Buckman (Memphis, Tenn., U.S.A.). This coating package contains adhesive chemistries to provide wet and dry tact, film forming chemistries to provide an even coating film, and modifying chemistries to harden or soften the coating to allow for proper removal of coating remaining at the cleaning blade. The web in the valley portions of the fabric was protected from compaction, while the web portion on the knuckles of the fabric (27% of the web) was lightly compacted at the pressure roll nip. The knuckle pattern was further imprinted into the web at this nip.

[0170] The web then traveled on the Yankee dryer and held in intimate contact with the Yankee surface by the coating chemistry. The Yankee was provided steam at 0.7 bar and 125 deg C, while the installed hot air impingement hood over the Yankee was blowing heated air at 450 deg C. The web was creped from the Yankee at 15% crepe using a ceramic blade at a pocket angle of 90 degrees. The caliper of the web was approximately 300 microns before traveling through the calender to reduce the bulk to 200 microns. The web was cut into two of equal width using a high pressure water stream at 10,000 psi and reeled into two equally sized parent rolls and transported to the converting process.

[0171] In the converting process, the two webs were plied together using mechanical ply bonding, or light embossing using the DEKO configuration (only the top sheet is embossed with glue applied to the inside of the top sheet at the high points derived from the embossments using an adhesive supplied by a cliché roll) with the second exterior layer of each web facing each other. The product was wound into a 425 sheet count product at 133 mm. Alternately, the web was not calendered on the paper machine and the web was converted as described above, but was wound into a 330 count product at 133 mm with nearly the same physical properties as described previously.

[0172] Alternately; in the converting process, the first exterior surface of the two webs were covered with a softener chemistry using a wet chemical applicator supplied by WEKO (Spartanburg, S.C., USA). The webs were then plied together using mechanical ply bonding and folded into a 2-ply facial product.

Example 2

[0173] A rolled 2-ply sanitary tissue product with 190 sheets, a roll firmness of 6.0, a roll diameter of 121 mm, with sheets having a length of 4.0 inches and width of 4.0 inches, was produced using a manufacturing method that utilized a structured fabric and belt press. The 2-ply tissue product further had the following product attributes: Basis Weight 39 g/m.sup.2, Caliper 550 mm, MD tensile strength of 165 N/m, CD tensile strength of 75 N/m, a ball burst of 230 grams force, a crumple resistance of 30 grams force, a peak to valley depth of 110 microns, a lint value of 5.5, an MD stretch of 14%, a CD stretch of 6%, and a CD wet tensile strength of 18 N/m.

[0174] The tissue web was multilayered with the fiber and chemistry of each layer selected and prepared individually to maximize product quality attributes of softness and strength. The first exterior layer, which was the layer intended for contact with the Yankee dryer, was prepared using 100% eucalyptus with 1.0 kg/ton of the amphoteric starch Redibond 2038 (for lint control) and 1.0 kg/ton of the glyoxylated polyacrylamide Hercobond 1194 (for strength when wet). The interior layer was composed of 40% northern bleached softwood kraft fibers, 60% eucalyptus fibers, and 1.5 kg/ton of T526, a softener/debonder. The second exterior layer was composed of 20% northern bleached softwood kraft fibers, 80% eucalyptus fibers and 1.0 kg/ton of Redibond 2038 (to limit refining and impart Z-direction strength). The eucalyptus in each layer was lightly refined at 15 kwh/ton to help facilitate better web bonding to the Yankee dryer, while the softwood was refined at 20 kwh/ton to impart the necessary tensile strength.

[0175] The fiber and chemicals mixtures were diluted to a solids of 0.5% consistency and fed to separate fan pumps which delivered the slurry to a triple layered headbox. The headbox pH was controlled to 7.0 by addition of a caustic to the thick stock before the fan pumps. The headbox deposited the slurry to a nip formed by a forming roll, an outer forming wire, and structured fabric. The slurry was drained through the outer wire, which was a KT194-P design supplied by Asten Johnson, to aid with drainage, fiber support, and web formation. When the fabrics separated, the web followed the structured fabric which contained a vacuum box inside the fabric run to facilitate with fiber penetration into the structured fabric to enhance bulk softness and web imprinting.

[0176] The structured fabric was a Prolux 005 design supplied by Albany (Rochester, N.H., USA) and was a 5 shed design with a warp pick sequence of 1,3,5,2,4, a 17.8 by 11.1 yarn/cm Mesh and Count, a 0.35 mm warp monofilament, a 0.50 mm weft monofilament, a 1.02 mm caliper, with a 640 cfm and a knuckle surface that was sanded to impart 27% contact area with the Yankee dryer. The web was transferred to a belt press assembly made up of a permeable belt which pressed the non-web contacting surface of the structured fabric while the web was nipped between a permeable dewatering fabric and a vacuum roll. The vacuum roll was through and blind drilled and supplied with 0.5 bar vacuum while the belt press was supplying 30 kN/meter loading and was of the BW2 design supplied by Voith. A hot air impingement hood installed in the belt press was heating the water in the web using a steam shower at 0.4 bar pressure and hot air at a temperature of 150 deg C. The heated water within the web was pressed into the dewatering fabric which was of the AX2 design supplied by Voith. A significant portion of the water that was pressed into the dewatering fabric was pulled into the vacuum roll blind and bored roll cover and then deposited into the save-all pan after the vacuum was broken at the outgoing nip between the belt press and vacuum roll. Water was also pulled through the vacuum roll and into a vacuum separator as the air stream was laden with moisture.

[0177] The web then traveled to a second press section and was nipped between the dewatering fabric and structured fabric using a hard and soft roll. The roll under the dewatering fabric was supplied with 0.5 bar vacuum to assist further with water removal. The web then traveled with the structured fabric to the suction pressure roll, while the dewatering fabric was conditioned using showers and a uhle box to remove contaminants and excess water. The web was nipped up to 50 pli of force at the pressure roll nip while 0.5 bar vacuum was applied to further remove water.

[0178] The web was now 50% solids and was transferred to the Yankee dryer that was coated with the Magnos coating package supplied by Buckman. This coating package contains adhesive chemistries to provide wet and dry tact, film forming chemistries to provide an even coating film, and modifying chemistries to harden or soften the coating to allow for proper removal of coating remaining at the cleaning blade. The web in the valley portion of the fabric was protected from compaction, while the web portion on the knuckles of the fabric (27% of the web) was lightly compacted at the pressure roll nip. The knuckle pattern was further imprinted into the web at this nip.

[0179] The web then traveled on the Yankee dryer and held in intimate contact with the Yankee surface by the coating chemistry. The Yankee provided steam at 0.7 bar and 125 deg C, while the installed hot air impingement hood over the Yankee was blowing heated air at 450 deg C. The web was creped from the Yankee at 15% crepe using a ceramic blade at a pocket angle of 90 degrees. The caliper of the web was approximately 375 microns before traveling through the calender to reduce the bulk to 275 microns. The web was cut into two of equal width using a high pressure water stream at 10,000 psi and reeled into two equally sized parent rolls and transported to the converting process.

[0180] In the converting process, the two webs were plied together using mechanical ply bonding, or light embossing of the DEKO configuration (only the top sheet is embossed with glue applied to the inside of the top sheet at the high points derived from the embossments using and adhesive supplied by a cliché roll) with the second exterior layer of each web facing each other. The product was wound into a 190 sheet count product at 121 mm. Alternately, the web was not calendered on the paper machine and the web was converted as described above, but was wound into a 176 count product at 121 mm with nearly the same physical properties as described previously.

[0181] Alternately; in the converting process, the first exterior surface of the two webs were covered with a softener chemistry using a wet chemical applicator supplied by WEKO. The webs were then plied together using mechanical ply bonding and folded into a 2-ply facial product.

Example 3

[0182] A rolled 2-ply sanitary tissue product with 425 sheets, a roll firmness of 6.5, a roll diameter of 133 mm, with sheets having a length of 4.25 inches and width of 4.0 inches, was produced using a manufacturing method that utilized a structured fabric and belt press. The 2-ply tissue product further had the following product attributes: Basis Weight 30 g/m.sup.2, Caliper 0.330 mm, MD tensile strength of 160 N/m, CD tensile strength of 65 N/m, a ball burst of 210 gf, a crumple resistance of 23.9 grams force, a peak to valley depth of 51.3 microns, a crumple resistance of 30 grams force, a peak to valley depth of 110 microns, a lint value of 5.5, an MD stretch of 14%, a CD stretch of 6%, and a CD wet tensile strength of 14 N/m.

[0183] The tissue web was multilayered with the fiber and chemistry of each layer selected and prepared individually to maximize product quality attributes of softness and strength. The first exterior layer, which was intended for contact with the Yankee dryer, was prepared using 100% eucalyptus with 1.0 kg/ton of the amphoteric starch Redibond 2038 and 1.0 kg/ton of the glyoxylated polyacrylamide Hercobond 1194. The interior layer was composed of 10% pre-refined and bleached cannabis fibers, 30% northern bleached softwood kraft fibers, 60% eucalyptus fibers, and 1.0 kg/ton of T526 a softener/debonder supplied by EKA. The second exterior layer was composed of 10% pre-refined and bleached cannabis fibers, 20% northern bleached softwood kraft fibers, 70% eucalyptus fibers and 1.0 kg/ton of Redibond 2038 (to limit refining and impart Z-direction strength). The eucalyptus in each layer was lightly refined at 15 kwh/ton to help facilitate better web bonding to the Yankee dryer, while the softwood was refined at 30 kwh/ton to impart the necessary tensile strength.

[0184] The fiber and chemicals mixtures were diluted to a solids of 0.5% consistency and fed to separate fan pumps which delivered the slurry to a triple layered headbox. The headbox pH was controlled to 7.0 by addition of a caustic to the thick stock before the fan pumps. The headbox deposited the slurry to a nip formed by two forming fabrics in a twin wire former configuration. The web was drained through the outer forming fabric, which was an Integra T design supplied by Asten Johnson, to aid with drainage, fiber support, and web formation. The inner wire was of the 194-P design from Asten Johnson, used for better web release and minimal fiber carryback. When the forming fabrics separates, the web followed the inner wire with the aid of a vacuum box installed under the inner wire.

[0185] The web was transferred to a structured fabric using 5% fabric crepe to generate additional caliper. The sheet was imprinted using a 4 slotted vacuum box with 1″ slots supplying 50 kPA of vacuum. The structured fabric was a P10 design supplied by Voith and was a 5 shed design with a warp pick sequence of 1,3,5,2,4, a 51 by 36 yarn/in Mesh and Count, a 0.30 mm warp monofilament, a 0.35 mm weft monofilament, a 0.79 mm caliper, with a 610 cfm and a knuckle surface that was sanded to impart 27% contact area with the Yankee dryer. The web was transferred to a belt press assembly made up of a permeable belt which pressed the non-web contacting surface of the structured fabric while the web was nipped between a permeable dewatering fabric and a vacuum roll. The vacuum roll was through and blind drilled and supplied with 0.5 bar vacuum while the belt press was supplying 30 kN/meter loading and was of the BW2 design supplied by Voith. A hot air impingement hood installed in the belt press was heating the water in the web using a steam shower at 0.4 bar pressure and hot air at a temperature of 150 deg C. The heated water within the web was pressed into the dewatering fabric which was of the AX2 design supplied by Voith. A significant portion of the water that was pressed into the dewatering fabric was pulled into the vacuum roll blind and bored roll cover and then deposited into the save-all pan after the vacuum was broken at the outgoing nip between the belt press and vacuum roll. Water was also pulled through the vacuum roll and into a separator as the air stream was laden with moisture.

[0186] The web then traveled to a second press section and was nipped between the dewatering fabric and structured fabric using a hard and soft roll. The roll under the dewatering fabric was supplied with 0.5 bar vacuum to assist further with water removal. The web then traveled with the structured fabric to the wire turning roll, while the dewatering fabric was conditioned using showers and a uhle box to remove contaminants and excess water. The wire turning roll was also supplied with 0.5 bar vacuum to aid in further water removal before the web was nipped between a suction pressure roll and the Yankee dryer. The web was nipped up to 50 pli of force at the pressure roll nip while 0.5 bar vacuum was applied to further remove water.

[0187] The web was then 50% solids and was transferred to the Yankee dryer that was coated with the Magnos coating package supplied by Buckman. This coating package contains adhesive chemistries to provide wet and dry tact, film forming chemistries to provide an even coating film, and modifying chemistries to harden or soften the coating to allow for proper removal of coating remaining at the cleaning blade. The web in the valley portions of the fabric was protected from compaction, while the web portion on the knuckles of the fabric (27% of the web) was lightly compacted at the pressure roll nip. The knuckle pattern was further imprinted into the web at this nip.

[0188] The web then traveled on the Yankee dryer and was held in intimate contact with the Yankee surface by the coating chemistry. The Yankee provided steam at 0.7 bar and 125 deg C, while the installed hot air impingement hood over the Yankee was blowing heated air at 450 deg C. The web was creped from the Yankee at 15% crepe using a ceramic blade at a pocket angle of 90 degrees. The caliper of the web was approximately 300 microns before traveling through the calendar to reduce the bulk to 200 microns. The web was cut into two of equal width using a high pressure water stream at 10,000 psi and reeled into two equally sized parent rolls and transported to the converting process.

[0189] In the converting process, the two webs were plied together using mechanical ply bonding, or light embossing using the DEKO configuration (only the top sheet is embossed with glue applied to the inside of the top sheet at the high points derived from the embossments using an adhesive supplied by a cliché roll) with the second exterior layer of each web facing each other. The product was wound into a 425 sheet count product at 133 mm. Alternately, the web was not calendared on the paper machine and the web was converted as described above, but was wound into a 330 count product at 133 mm with nearly the same physical properties as described previously.

[0190] Alternately; in the converting process, the first exterior surface of the two webs were covered with a softener chemistry using a wet chemical applicator supplied by WEKO. The webs were then plied together using mechanical ply bonding and folded into a 2-ply facial product.

Example 4

[0191] A rolled 2-ply sanitary tissue product with 190 sheets, a roll firmness of 6.0, a roll diameter of 121 mm, with sheets having a length of 4.0 inches and width of 4.0 inches, was produced using a manufacturing method that utilizes a structured fabric and belt press. The 2-ply tissue product further had the following product attributes: Basis Weight 39 g/m.sup.2, Caliper 0.550 mm, MD tensile strength of 165 N/m, CD tensile strength of 75 N/m, a ball burst of 230 gf, a lint value of 5.5, an MD stretch of 14%, a CD stretch of 6%, and a CD wet tensile strength of 18 N/m.

[0192] The tissue web was multilayered with the fiber and chemistry of each layer selected and prepared individually to maximize product quality attributes of softness and strength. The first exterior layer, which was the layer intended for contact with the Yankee dryer, was prepared using 100% eucalyptus with 1.0 kg/ton of the amphoteric starch Redibond 2038 (for lint control) and 1.0 kg/ton of the glyoxylated polyacrylamide Hercobond 1194 (for strength when wet). The interior layer was composed of 40% northern bleached softwood kraft fibers, 60% eucalyptus fibers, and 1.5 kg/ton of T526, a softener/debonder. The second exterior layer was composed of 20% northern bleached softwood kraft fibers, 80% eucalyptus fibers and 1.0 kg/ton of Redibond 2038 (to limit refining and impart Z-direction strength). The eucalyptus in each layer was lightly refined at 15 kwh/ton to help facilitate better web bonding to the Yankee dryer, while the softwood was refined at 20 kwh/ton to impart the necessary tensile strength.

[0193] The fiber and chemical mixtures were diluted to a solids of 0.5% consistency and fed to separate fan pumps which delivered the slurry to a triple layered headbox. The headbox pH was controlled to 7.0 by addition of a caustic to the thick stock before the fan pumps. The headbox deposited the slurry to a nip formed by two forming fabrics in a twin wire former configuration. The web was drained through the outer forming fabric, which was an Integra T design supplied by Asten Johnson, to aid with drainage, fiber support, and web formation. The inner wire was of the 194-P design from Asten Johnson, used for better web release and minimal fiber carryback. When the forming fabrics separate, the web followed the inner wire with the aid of a vacuum box installed under the inner wire.

[0194] The web was transferred to a structured fabric using 0% fabric crepe. The sheet was imprinted using a 4 slotted vacuum box with 1″ slots supplying 50 kPA of vacuum. The structured fabric was a Prolux 005 design supplied by Albany and was a 5 shed design with a warp pick sequence of 1,3,5,2,4, a 17.8 by 11.1 yarn/cm Mesh and Count, a 0.35 mm warp monofilament, a 0.50 mm weft monofilament, a 1.02 mm caliper, with a 640 cfm and a knuckle surface that was sanded to impart 27% contact area with the Yankee dryer. The web was transferred to a belt press assembly made up of a permeable belt which pressed the non-web contacting surface of the structured fabric while the web was nipped between a permeable dewatering fabric and a vacuum roll. The vacuum roll was through and blind drilled and supplied with 0.5 bar vacuum while the belt press was supplying 30 kN/meter loading and was of the BW2 design supplied by Voith. A hot air impingement hood installed in the belt press was heating the water in the web using a steam shower at 0.4 bar pressure and hot air at a temperature of 150 deg C. The heated water within the web was pressed into the dewatering fabric which was of the AX2 design supplied by Voith. A significant portion of the water that was pressed into the dewatering fabric was pulled into the vacuum roll blind and bored roll cover and then deposited into the save-all pan after the vacuum was broken at the outgoing nip between the belt press and vacuum roll. Water was also pulled through the vacuum roll and into a vacuum separator as the air stream was laden with moisture.

[0195] The web then traveled to a second press section and was nipped between the dewatering fabric and structured fabric using a hard and soft roll. The roll under the dewatering fabric was supplied with 0.5 bar vacuum to assist further with water removal. The web then traveled with the structured fabric to the wire turning roll, while the dewatering fabric was conditioned using showers and a uhle box to remove contaminants and excess water. The wire turning roll was also supplied with 0.5 bar vacuum to aid in further water removal before the web was nipped between a suction pressure roll and the Yankee dryer. The web was nipped up to 50 pli of force at the pressure roll nip while 0.5 bar vacuum was applied to further remove water.

[0196] The web was then 50% solids and was transferred to the Yankee dryer that was coated with the Magnos coating package supplied by Buckman. This coating package contains adhesive chemistries to provide wet and dry tact, film forming chemistries to provide an even coating film, and modifying chemistries to harden or soften the coating to allow for proper removal of coating remaining at the cleaning blade. The web in the valley portion of the fabric was protected from compaction, while the web portion on the knuckles of the fabric (27% of the web) was lightly compacted at the pressure roll nip. The knuckle pattern was further imprinted into the web at this nip.

[0197] The web then traveled on the Yankee dryer and was held in intimate contact with the Yankee surface by the coating chemistry. The Yankee was provided steam at 0.7 bar and 125 deg C, while the installed hot air impingement hood over the Yankee was blowing heated air at 450 deg C. The web was creped from the Yankee at 15% crepe using a ceramic blade at a pocket angle of 90 degrees. The caliper of the web was approximately 375 microns before traveling through the calendar to reduce the bulk to 275 microns. The web was cut into two of equal width using a high pressure water stream at 10,000 psi and reeled into two equally sized parent rolls and transported to the converting process.

[0198] In the converting process, the two webs were plied together using mechanical ply bonding, or light embossing of the DEKO configuration (only the top sheet is embossed with glue applied to the inside of the top sheet at the high points derived from the embossments using and adhesive supplied by a cliché roll) with the second exterior layer of each web facing each other. The product was wound into a 190 sheet count product at 121 mm. Alternately, the web was not calendared on the paper machine and the web was converted as described above, but was wound into a 176 count product at 121 mm with nearly the same physical properties as described previously.

[0199] Alternately; in the converting process, the first exterior surface of the two webs were covered with a softener chemistry using a wet chemical applicator supplied by WEKO. The webs were then plied together using mechanical ply bonding and folded into a 2-ply facial product.

[0200] Table 1 below provides values for the peak-to-valley depth, crumple resistance and bulk (caliper) of Examples 1-4 as compared to conventional products made by either conventional creping, TAD, NTT, ETAD or UCTAD processes. As can be appreciated from the data, the tissue products of Examples 1-4 generally exhibit greater peak to valley depth and bulk as compared to conventionally creped products along with reduced crumple resistance as compared to other 2-ply tissue products made using a structured fabric. A tissue product according to an exemplary embodiment of the present invention is a structured tissue having at least two plies, wherein the tissue has a crumple resistance of less than 30 grams force, an average peak to valley depth of at least 65 microns, preferably at least 100 microns, and a caliper of at least 450 microns/2 ply. Further, the use of both structured fabric and creping in the inventive process results in two distinct microstructure patterns formed in the tissue web, as opposed to only a single microstructure pattern formed in products made using only conventional creping.

TABLE-US-00001 TABLE 1 Peak to Crumple Valley Depth resistance Number Basis Wt Bulk PRODUCT Technology [microns] [g-Force] of Plies [gsm] [microns] EXAMPLE 1 ATMOS 51 23.9 2 31 271 EXAMPLE 2 ATMOS 110 29.0 2 39 620 EXAMPLE 3 ATMOS 44 29.0 2 31 329 EXAMPLE 4 ATMOS 108 25.0 2 39 550 Kroger Conventional 27 12.6 1 17 168 Creping Sam's Club Mexico NTT 27 20.0 2 33 273 Walmart Southeast - Conventional 48 42.8 3 56 538 Quilted Northern Ultra Creping Costco Southeast - Conventional 55 21.0 2 38 327 Kirkland Signature Creping Walmart Southeast - Conventional 61 29.4 2 37 477 Angel Soft Creping Canada East - Pres TAD 101 50.8 2 46 489 Choice Max Walmart Southeast - TAD 142 31.6 2 47 488 Charmin Soft MEGA Walmart West - Great TAD 144 45.9 2 47 454 Value Ultra Soft Walmart Southeast - TAD 150 43.0 2 38 406 Charmin Strong MEGA Walmart Southeast - TAD 154 47.1 2 47 580 Charmin Soft Regular Walmart West - Quilted ETAD 163 37.7 2 46 501 Northern Soft and Strong Walmart Southeast - TAD 166 25.7 1 31 347 Charmin Basic Walmart Southeast - TAD 167 48.6 2 36 386 Charmin Strong Reg Roll Sam's Club Mexico NTT 192 25.7 2 31 401 First Quality Soft Bath TAD 220 40.4 2 39 624 First Quality Strong Bath TAD 245 43.9 2 36 589 Walmart Southeast - UCTAD 468 81.2 1 40 601 Cottonelle Clean Care Walmart Southeast - UCTAD 473 65.9 2 43 702 Cottonelle Ultra

[0201] As known in the art, the tissue web is subjected to a converting process at or near the end of the web forming line to improve the characteristics of the web and/or to convert the web into finished products. On the converting line, the tissue web may be unwound, printed, embossed and rewound. According to an exemplary embodiment of the invention, the paper web on the converting lines may be treated with corona discharge before the embossing section. This treatment may be applied to the top ply and/or bottom ply. Nano cellulose fibers (NCF), nano crystalline cellulose (NCC), micro-fibrillated cellulose (MCF) and other shaped natural and synthetic cellulose based fibers may be blown on to the paper web using a blower system immediately after corona treatment. This enables the nano-fibers to adsorb on to the paper web through electro-static interactions.

[0202] Now that embodiments of the present invention have been shown and described in detail, various modifications and improvements thereon will become readily apparent to those skilled in the art. Accordingly, the spirit and scope of the present invention is to be construed broadly and not limited by the foregoing specification.