BACKGROUND

Consumers desire a soft tissue, but they also want a tissue that is absorbent and wets out slowly so as to protect their hands in use. The consumers' desires present a dilemma for the tissue maker - increase softness using additives that impair absorbency and barrier properties or increase absorbency and barrier properties using additives at the expense of softness. In an attempt to balance softness and absorbent properties, tissue makers have resorted to the use of additives in the wet-end of the tissue making process or post-treating the manufactured tissue web. One particular class of additives tissue makers have employed is surfactants. For example, US Publication No. 2014/0050889 describes post- treatment of a tissue web with a surfactant to improve absorbency. On the other-hand, US Patent No. 5,730,839 describes adding surfactants during formation of the tissue web, prior to drying. While providing certain benefits, these methods of enhancing absorbent properties increase operational costs, add complexities, and may negatively affect creping, which in-turn may decrease softness.

Thus, there remains a need for an efficient, simple method of enhancing absorbent properties without negatively affecting softness.

SUMMARY

The present inventors have now discovered that surfactants may be added at the creping stage to not only improve absorbent properties, but also improve crepe structure and increase softness. The absorbent properties strike a balance between absorption of nasal discharge, on the one hand, and protection from the same, on the other. At the same time the tissue has a fine crepe structure and the softness imparted thereby. Accordingly, in one embodiment the present disclosure provides a creped tissue product having a moderate degree of moisture resistance, such as a Hercules Size Test (HST) value from about 2 to about 8 seconds, and a controlled time to saturation, such as a Wet Out time from about 5 to about 30 seconds.

In other embodiments the present disclosure provides a creped tissue product having a Hercules Size Test (HST) value from about 2 to about 8 seconds and Wet Out time greater than about 5 seconds and a TS7 value less than about 10.0. In still other embodiments the present disclosure provides a creped tissue product having a fine crepe structure less than 15 percent COV, measured at a wavelength from 8-16 mm, a Hercules Size Test (HST) value from about 2 to about 8 seconds and Wet Out time from about 5 to about 30 seconds. In yet other embodiments the present disclosure provides a creped tissue product comprising at least one web having a first side and a second side and a creping composition comprising a non-fibrous olefin polymer and a nonionic surfactant disposed on at least the first side, wherein the tissue product has a TS7 value less than about 10, a Hercules Size Test (HST) value from about 2 to about 8 seconds and Wet Out time from about 5 to about 30 seconds.

In other embodiments the present disclosure provides a method of forming a soft creped tissue web comprising the steps of forming an aqueous slurry of paper making fibers; dewatering the aqueous slurry to form a base sheet; applying a creping composition comprising a surfactant and a olefin polymer to a moving creping surface; pressing the base sheet against the creping surface after the creping composition has been applied; and removing the base sheet from the creping surface.

DEFINITIONS

As used herein, the term "Hercules Size Test" (HST) is a measure of the resistance of a tissue sample to permeation of an aqueous penetrant and is determined as described in the Test Methods section.

As used herein, the term "Wet Out" generally refers to the time required to saturate a tissue sample with a liquid and is determined as described in the Test Methods section.

As used herein, the term "Geometric Mean Tensile" (GMT) refers to the square root of the product of the machine direction tensile and the cross-machine direction tensile of the web, which are determined as described in the Test Methods section.

As used herein, the term "Slope," also referred to as "modulus," refers to slope of the line resulting from plotting tensile versus stretch and is an output of the MTS TestWorks™ in the course of determining the tensile strength as described in the Test Methods section. Slope is reported in the units of grams (g) per unit of sample width (inches) and is measured as the gradient of the least-squares line fitted to the load-corrected strain points falling between a specimen- generated force of 70 to 157 grams (0.687 to 1.540 N) divided by the specimen width.

As used herein, the term "GM Slope" generally refers to the square root of the product of the machine direction and cross-machine direction slopes, and is an output of the MTS TestWorks™ in the course of determining the tensile strength as described in the Test Methods section.

As used therein the term "Stiffness Index" refers to the quotient of the GM Slope (having units of grams) divided by the Geometric Mean Tensile (having units grams).

As used herein, the term "tissue product" refers to products made from base webs comprising fibers and includes, bath tissues, facial tissues, paper towels, industrial wipers, foodservice wipers, napkins, medical pads, and other similar products.

As used herein, the terms "tissue web" and "tissue sheet" refer to a cellulosic web suitable for making for use as a tissue product.

As used herein, the term "caliper" is the representative thickness of a single sheet measured in accordance with TAPPI test methods T402 "Standard Conditioning and Testing Atmosphere For Paper, Board, Pulp Handsheets and Related Products" and T411 om-89 "Thickness (caliper) of Paper, Paperboard, and Combined Board" with Note 3 for stacked sheets. The micrometer used for carrying out T411 om-89 is an Emveco 200-A Tissue Caliper Tester (Emveco, Inc., Newberg, OR). The micrometer has a load of 2 kilo- Pascals, a pressure foot area of 2500 square millimeters, a pressure foot diameter of 56.42 millimeters, a dwell time of 3 seconds and a lowering rate of 0.8 millimeters per second. Caliper may be expressed in mils (0.001 inches) or microns.

As used herein the term "basis weight" generally refers to the conditioned dry weight per unit area of a tissue and is generally expressed as grams per square meter (gsm). Basis weight is measured herein using TAPPI test method T-220.

DETAILED DESCRIPTION

In general, the present disclosure is directed to creped tissue webs, and products produced therefrom. The creped tissue webs and products are strong, soft, and have desirable absorbent properties such as a Wet Out time greater than 5 seconds and an HST value from about 2 to about 8 seconds. As such, the inventive tissues are somewhat resistant to the permeation of liquids and saturate relatively slowly. This balance of permeation and saturation provides a tissue that is absorbent, yet protects the user's hands in-use. Surprisingly, these desirable absorbent properties are achieved without sacrificing softness. As such, the tissue products disclosed herein generally have a TS7 value less than about 10.0 and more preferably less than about 9.0, such as from about 8.0 to about 9.0. The tissues also have a fine crepe structure, such as less than about 15 percent COV, measured at a wavelength from 8-16 mm.

The balance of softness and absorbency is generally achieved by the use of a creping composition comprising an olefin polymer and a surfactant. In this manner the inventive tissue products are achieved without the addition of processing steps, such as additions to the wet tissue making furnish or post treatment of the web with an oil, a wax, a silicone, a fatty alcohol, or a lotion comprising one or more emollients. Further, the favorable absorption and crepe properties may be achieved without the addition of sizing agents, such as alkyl ketene dimers, alkenyl succinic anhydride, rosin size, long chain hydrocarbon anhydrides, organic isocyanates, alkyl carbamyl chlorides, alkylated melamines, styrene acrylics, styrene maleic anhydride, styrene acrylate emulsions, and hydroxyethylated starches.

Accordingly, in one embodiment, the tissue webs are creped, wherein the creping composition comprises a thermoplastic resin, such as the composition disclosed in US Patent No. 7,807,023, which is incorporated herein in a manner consistent with the present disclosure. The thermoplastic resin may be contained, for instance, in an aqueous dispersion prior to application to the creping surface. In one particular embodiment, the creping composition may comprise a non-fibrous olefin polymer. The creping composition, for instance, may comprise a film-forming composition and the olefin polymer may comprise a copolymer of ethylene and at least one comonomer comprising an alkene, such as 1-octene. The creping composition may also contain a dispersing agent, such as a carboxylic acid. Examples of particular dispersing agents, for instance, include fatty acids, such as oleic acid or stearic acid.

In one particular embodiment, the creping composition may contain an ethylene and octene copolymer in combination with an ethylene- acrylic acid copolymer. The ethylene- acrylic acid copolymer is not only a thermoplastic resin, but may also serve as a dispersing agent. The ethylene and octene copolymer may be present in combination with the ethylene-acrylic acid copolymer in a weight ratio of from about 1: 10 to about 10: 1, such as from about 2:3 to about 3:2.

The olefin polymer composition may exhibit a crystallinity of less than about 50 percent, such as less than about 20 percent. The olefin polymer may also have a melt index of less than about 1000 g/10 min, such as less than about 700 g/10 min. The olefin polymer may also have a relatively small particle size, such as from about 0.05 to about 5 microns when contained in an aqueous dispersion.

In an alternative embodiment, the creping composition may contain an ethylene- acrylic acid copolymer. The ethylene-acrylic acid copolymer may be present in the creping composition in combination with a dispersing agent, such as a fatty acid.

In addition to an olefin polymer, the creping composition preferably comprises a surfactant. The surfactant may be provided in an amount between about 0.01 and 3 percent by weight, preferably 0.1 and 1 percent by weight, based on the total amount of the polymer dispersion. The surfactant may comprise a single surfactant or a blend of surfactants. The surfactants contemplated for the invention include any of the known and conventional surfactants, principally the nonionic and anionic surfactants. Particularly preferred surfactants are the nonionic surfactants, which include compounds selected from the group consisting of straight chain fatty alcohols containing from about 6 to about 20 carbon atoms, branched chain fatty alcohols containing from about 6 to about 20 carbon atoms, secondary fatty alcohols containing from about 6 to about 20 carbon atoms, branched alcohol ethoxylates condensed with an average of from about 6 to about 15 moles of ethylene oxide per mole of alcohol, secondary alcohol ethoxylates condensed with an average of from about 6 to about 15 moles of ethylene oxide per mole of alcohol, and mixtures thereof. In particularly preferred embodiments the nonionic surfactant component of the stabilizing system may comprise an oxyalkylated product of an alkyl phenol, an aliphatic alcohol, an aliphatic carboxylic acid, or an acetylenic glycol or block copolymers of ethylene oxide and propylene oxide.

Particularly preferred nonionic surfactants are alkoxylated alkylphenols, such as those sold under the trade name Lutensol® (BASF) and octylphenol ethoxylates, such as those sold under the trade name Triton (Dow Chemical). Other preferred nonionic surfactants are alkylphenoxy-poly(ethyleneoxy)ethanols having alkyl groups containing from about 7 to 18 carbon atoms, and having from about 4 to 100 ethyl eneoxy units, such as the octylphenoxy poly(ethyleneoxy)ethanols, nonylphenoxy poly(ethyleneoxy)ethanols, and dodecylphenoxy poly(ethyleneoxy)ethanols. Other examples of nonionic surfactants include polyoxyalkylene derivatives of hexitol (including sorbitans, sorbides, manitans, and mannides) anhydride, partial long-chain fatty acid esters, such as polyoxyalkylene derivatives of sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan tristearate, sorbitan monooleate and sorbitan trioleate.

In certain preferred embodiments the creping composition comprises from about 0.5 to about 3.0 percent, by weight of the creping composition, surfactant and still more preferably from about 1.0 to about 2.5 percent, by weight of the creping composition. The surfactants are generally applied to the creping cylinder at add-on levels from about

0.5 mg/m 2 to about 5 mg/m 2. In a particularly preferred embodiment the creping composition comprises an olefin polymer and a nonionic surfactant, where the nonionic surfactant comprises from about 1.0 to about 2.5 percent, by weight of the creping composition.

Tissues prepared according to the present disclosure generally saturate slowly having Wet Out times greater than about 5 seconds, such as from about 5 to about 30 seconds and more preferably from about 5 to about 20 seconds. The tissues also resist liquid permeation having HST values from about 2 to 8 seconds and more preferably from about 2 to about 6 seconds. This combination of absorption properties is not found in commercially available tissue as illustrated in Table 1, below.

TABLE 1

Accordingly, in certain embodiments the disclosure provides a creped tissue product comprising two or more plies, wherein the product has a basis weight of at least about 25 grams per square meter (gsm) and more preferably at least about 30 gsm, such as from about 30 to about 40 gsm. At these basis weights the tissue products of the present invention have geometric mean tensile less than about 1200 g/3" and more preferably less than about 1100 g/3" and still more preferably less than about 1000 g/3", such as from about 750 to about 1000 g/3".

At the foregoing basis weights and tensile strengths, the inventive tissue products generally have GM Slope less than about 20 kg/3", such as from about 14 to about 18 kg/3" and more preferably from about 16 to about 18 kg/3". As such the tissue products generally have a Stiffness Index less than about 20, such as from about 14 to about 20 and more preferably from about 16 to about 18.

In addition to having improved absorption properties, tissue webs and products prepared according to the present disclosure have excellent softness and fine crepe structure. For example, tissue webs prepared according to the present invention generally have a tissue softness value (also referred to herein as a "TS7 value"), measured using EMTEC Tissue Softness Analyzer ("TSA") (Emtec Electronic GmbH, Leipzig, Germany) as described in the Test Methods section, less than about 10.0, such as from about 8.0 to about 10.0. Accordingly, in a particularly preferred embodiment the present disclosure provides a tissue product having an HST value from about 2 to about 8 seconds, a Wet Out time from about 5 to about 30 seconds and a TS7 value from about 8.0 to about 10.0.

In still other embodiments the inventive tissues not only have desirable absorbent properties, such as an HST value from about 2 to about 8 seconds and a Wet Out time from about 5 to about 30 seconds, but are also soft, having a TS7 value less than about 10.0, more preferably less than about 9.0, such as from about 8.0 to about 9.0.

In other embodiments tissue prepared according to the present invention also has a fine crepe structure. In certain embodiments the present invention provides a tissue web having a fine crepe structure less than 15 percent COV, measured at a wavelength from 8 to 16 mm, such as from about 10 to about 15 percent COV and more preferably from about 13 to about 15 percent COV. In a particularly preferred embodiment the present disclosure provides a tissue product having a fine crepe structure less than 15 percent COV, measured at a wavelength from 8 to 16 mm, an HST value from about 2 to about 8 seconds and a Wet Out time from about 5 to about 30 seconds.

TABLE 2

In general, any suitable fibrous web may be treated in accordance with the present disclosure. For example, in one aspect, the base sheet can be a tissue product, such as a bath tissue, a facial tissue, a paper towel, a napkin, and the like. Fibrous products can be made from any suitable types of fiber. Fibrous products made according to the present disclosure may include single-ply fibrous products or multiple-ply fibrous products. For instance, in some aspects, the product may include two plies, three plies, or more. Fibers suitable for making fibrous webs comprise any natural or synthetic fibers including both nonwoody fibers and woody or pulp fibers. Pulp fibers can be prepared in high-yield or low-yield forms and can be pulped in any known method, including kraft, sulfite, high-yield pulping methods and other known pulping methods. Fibers prepared from organosolv pulping methods can also be used, including the fibers and methods disclosed in US Patent Nos. 4,793,898, 4,594,130, and 3,585,104. Useful fibers can also be produced by anthraquinone pulping, exemplified by US Patent No. 5,595,628.

The fibrous webs of the present disclosure can also include synthetic fibers. For instance, the fibrous webs can include up to about 10 percent, such as up to about 30 percent or up to about 50 percent or up to about 70 percent or more by dry weight, to provide improved benefits. Suitable synthetic fibers include rayon, polyolefin fibers, polyester fibers, bicomponent sheath-core fibers, multi-component binder fibers, and the like. Synthetic cellulose fiber types include rayon in all its varieties and other fibers derived from viscose or chemically-modified cellulose. Chemically treated natural cellulosic fibers can be used, for example, mercerized pulps, chemically stiffened or crosslinked fibers, or sulfonated fibers. For good mechanical properties in using web forming fibers, it can be desirable that the fibers be relatively undamaged and largely unrefined or only lightly refined. While recycled fibers can be used, virgin fibers are generally useful for their mechanical properties and lack of contaminants. Mercerized fibers, regenerated cellulosic fibers, cellulose produced by microbes, rayon, and other cellulosic material or cellulosic derivatives can be used. Suitable web forming fibers can also include recycled fibers, virgin fibers, or mixes thereof. In general, any process capable of forming a web can also be utilized in the present disclosure. For example, a web forming process of the present disclosure can utilize creping, wet creping, double creping, recreping, double recreping, embossing, wet pressing, air pressing, through-air drying, hydroentangling, creped through-air drying, co-forming, airlaying, as well as other processes known in the art. For hydroentangled material, the percentage of pulp is about 70 to 85 percent.

Also suitable for articles of the present disclosure are fibrous sheets that are pattern densified or imprinted, such as the fibrous sheets disclosed in any of the following US Patent Nos. 4,514,345, 4,528,239, 5,098,522, 5,260,171, and 5,624,790, the disclosures of which are incorporated herein by reference to the extent they are non-contradictory herewith. Such imprinted fibrous sheets may have a network of densified regions that have been imprinted against a drum dryer by an imprinting fabric, and regions that are relatively less densified (e.g., "domes" in the fibrous sheet) corresponding to deflection conduits in the imprinting fabric, wherein the fibrous sheet superposed over the deflection conduits was deflected by an air pressure differential across the deflection conduit to form a lower- density pillow-like region or dome in the fibrous sheet.

The fibrous web can also be formed without a substantial amount of inner fiber-to- fiber bond strength. In this regard, the fiber furnish used to form the base web can be treated with a chemical debonding agent. The debonding agent can be added to the fiber slurry during the pulping process or can be added directly to the headbox. Suitable debonding agents that may be used in the present disclosure include cationic debonding agents such as fatty dialkyl quaternary amine salts, mono fatty alkyl tertiary amine salts, primary amine salts, imidazoline quaternary salts, silicone, quaternary salt and unsaturated fatty alkyl amine salts. Other suitable debonding agents are disclosed in US Patent No. 5,529,665, which is incorporated herein by reference in a manner consistent herewith.

Fibrous webs that may be treated in accordance with the present disclosure may include a single homogenous layer of fibers or may include a stratified or layered construction. For instance, the fibrous web ply may include two or three layers of fibers. Each layer may have a different fiber composition. For example a three-layered headbox generally includes an upper headbox wall and a lower headbox wall. Headbox further includes a first divider and a second divider, which separate three fiber stock layers.

Each of the fiber layers comprises a dilute aqueous suspension of papermaking fibers. The particular fibers contained in each layer generally depend upon the product being formed and the desired results. For instance, the fiber composition of each layer may vary depending upon whether a bath tissue product, facial tissue product or paper towel product is being produced. In one aspect, for instance, the middle layer contains southern softwood kraft fibers either alone or in combination with other fibers such as high yield fibers. Outer layers, on the other hand, contain softwood fibers, such as northern softwood kraft. In an alternative aspect, the middle layer may contain softwood fibers for strength, while the outer layers may comprise hardwood fibers, such as eucalyptus fibers, for a perceived softness.

In general, any process capable of forming a base sheet may be utilized in the present disclosure. For example, an endless traveling forming fabric, suitably supported and driven by rolls, receives the layered papermaking stock issuing from the headbox.

Once retained on the fabric, the layered fiber suspension passes water through the fabric.

Water removal is achieved by combinations of gravity, centrifugal force and vacuum suction depending on the forming configuration. Forming multi-layered paper webs is also described and disclosed in US Patent No. 5,129,988, which is incorporated herein by reference in a manner that is consistent herewith.

Preferably the formed web is dried by transfer to the surface of a rotatable heated dryer drum, such as a Yankee dryer. In accordance with the present disclosure, the creping composition may be applied topically to the tissue web while the web is traveling on the fabric or may be applied to the surface of the dryer drum for transfer onto one side of the tissue web. In this manner, the creping composition is used to adhere the tissue web to the dryer drum. In this embodiment, as the web is carried through a portion of the rotational path of the dryer surface, heat is imparted to the web causing most of the moisture contained within the web to be evaporated. The web is then removed from the dryer drum by a creping blade. Creping the web, as it is formed, further reduces internal bonding within the web and increases softness. Applying the creping composition to the web during creping, on the other hand, may increase the strength of the web.

In another embodiment the formed web is transferred to the surface of the rotatable heated dryer drum, which may be a Yankee dryer. The press roll may, in one embodiment, comprise a suction pressure roll. In order to adhere the web to the surface of the dryer drum, a creping adhesive may be applied to the surface of the dryer drum by a spraying device. The spraying device may emit a creping composition made in accordance with the present disclosure or may emit a conventional creping adhesive. The web is adhered to the surface of the dryer drum and then creped from the drum using the creping blade. If desired, the dryer drum may be associated with a hood. The hood may be used to force air against or through the web. In other embodiments, once creped from the dryer drum, the web may be adhered to a second dryer drum. The second dryer drum may comprise, for instance, a heated drum surrounded by a hood. The drum may be heated from about 25°C to about 200°C, such as from about 100°C to about 150°C.

In order to adhere the web to the second dryer drum, a second spray device may emit an adhesive onto the surface of the dryer drum. In accordance with the present disclosure, for instance, the second spray device may emit a creping composition as described above. The creping composition not only assists in adhering the tissue web to the dryer drum, but also is transferred to the surface of the web as the web is creped from the dryer drum by the creping blade. Once creped from the second dryer drum, the web may, optionally, be fed around a cooling reel drum and cooled prior to being wound on a reel.

In addition to applying the creping composition during formation of the fibrous web, the creping composition may also be used in post-forming processes. For example, in one aspect, the creping composition may be used during a print-creping process. Specifically, once topically applied to a fibrous web, the creping composition has been found well-suited to adhering the fibrous web to a creping surface, such as in a print- creping operation. For example, once a fibrous web is formed and dried the creping composition may be applied to at least one side of the web and the at least one side of the web may then be creped. In general, the creping composition may be applied to only one side of the web and only one side of the web may be creped, the creping composition may be applied to both sides of the web and only one side of the web is creped, or the creping composition may be applied to each side of the web and each side of the web may be creped.

In one embodiment the creping composition may be added to one side of the web by creping, using either an in-line or off-line process. A tissue web is passed through a first creping composition application station that includes a nip formed by a smooth rubber press roll and a patterned rotogravure roll. The rotogravure roll is in communication with a reservoir containing a first creping composition. The rotogravure roll applies the creping composition to one side of the web in a preselected pattern. The web is then contacted with a heated roll, which can be heated to a temperature, for instance, up to about 200°C, and more preferably from about 100°C to about 150°C. In general, the web can be heated to a temperature sufficient to dry the web and evaporate any water. It should be understood, that besides the heated roll, any suitable heating device can be used to dry the web. For example, in an alternative embodiment, the web can be placed in communication with an infra-red heater in order to dry the web. Besides using a heated roll or an infra-red heater, other heating devices can include, for instance, any suitable convective oven or microwave oven.

From the heated roll, the web can be advanced by pull rolls to a second creping composition application station, which includes a transfer roll in contact with a rotogravure roll, which is in communication with a reservoir containing a second creping composition. The second creping composition may be applied to the opposite side of the web in a preselected pattern. The first and second creping compositions may contain the same ingredients or may contain different ingredients. Alternatively, the creping compositions may contain the same ingredients in different amounts as desired. Once the second creping composition is applied the web is adhered to a creping roll by a press roll and carried on the surface of the creping drum for a distance and then removed therefrom by the action of a creping blade. The creping blade performs a controlled pattern creping operation on the second side of the tissue web. Although the creping composition is being applied to each side of the tissue web, only one side of the web undergoes a creping process. It should be understood, however, that in other embodiments both sides of the web may be creped.

Once creped the tissue web may be pulled through a drying station. The drying station can include any form of heating unit, such as an oven energized by infra-red heat, microwave energy, hot air, or the like. A drying station may be necessary in some applications to dry the web and/or cure the creping composition. Depending upon the creping composition selected, however, in other applications a drying station may not be needed.

The creping compositions of the present disclosure are typically transferred to the web at high levels, such that at least about 30 percent of the creping composition applied to the Yankee is transferred to the web, more preferably at least about 45 percent is transferred and still more preferably at least about 60 percent is transferred. Generally from about 45 to about 65 percent of the creping composition applied to the Yankee dryer is transferred to the web. Thus, the amount of creping additive transferred to the sheet is a function of the amount of creping additive applied to the Yankee dryer.

The total amount of creping composition applied to the web can be in the range of from about 0.1 to about 10 percent by weight, based upon the total weight of the web, such as from about 0.3 to about 5 percent by weight, such as from about 0.5 to about 3 percent by weight. To achieve the desired additive application levels the add on rate of creping composition to the dryer, measured as mass (i.e., mg) per unit area of dryer surface

(i.e., m 2 ), may range from about 50 to about 300 mg/m 2 , and still more preferably from about 100 to about 200 mg/m . In a particularly preferred embodiment the creping composition comprises an olefin polymer, which is added at levels from about 100 to about

200 mg/m and a non-ionic surfactant, which is added at levels from about 0.5 to about 5 mg/m ² .

Further, the creping composition is applied to the paper web so as to cover from about 15 to about 100 percent of the surface area of the web. More particularly, in most applications, the creping composition will cover from about 20 to about 60 percent of the surface area of the web. In one aspect, fibrous webs made according to the present disclosure can be incorporated into multiple-ply products. For instance, in one aspect, a fibrous web made according to the present disclosure can be attached to one or more other fibrous webs for forming a wiping product having desired characteristics. The other webs laminated to the fibrous web of the present disclosure can be, for instance, a wet-creped web, a calendered web, an embossed web, a through-air dried web, a creped through-air dried web, an uncreped through-air dried web, an airlaid web, and the like.

In one aspect, when incorporating a fibrous web made according to the present disclosure into a multiple-ply product, it may be desirable to only apply the creping composition to one side of the fibrous web and to thereafter crepe the treated side of the web. The creped side of the web is then used to form an exterior surface of a multiple-ply product. The untreated and uncreped side of the web, on the other hand, is attached by any suitable means to one or more plies.

TEST METHODS

Tissue Softness (TSA)

Sample softness was analyzed using an EMTEC Tissue Softness Analyzer ("TSA") (Emtec Electronic GmbH, Leipzig, Germany). The TSA comprises a rotor with vertical blades which rotate on the test piece applying a defined contact pressure. Contact between the vertical blades and the test piece creates vibrations, which are sensed by a vibration sensor. The sensor then transmits a signal to a PC for processing and display. The signal is displayed as a frequency spectrum. The frequency analysis in the range of approximately 200 to 1000 Hz represents the surface smoothness or texture of the test piece. A high amplitude peak correlates to a rougher surface. A further peak in the frequency range between 6 and 7 kHz represents the softness of the test piece. The peak in the frequency range between 6 and 7 kHz is herein referred to as the TS7 Softness Value and is expressed as dB V2 rms. The lower the amplitude of the peak occurring between 6 and 7 kHz, the softer the test piece.

Test samples were prepared by cutting a circular sample having a diameter of 112.8 mm. All samples were allowed to equilibrate at TAPPI standard temperature and humidity conditions for at least 24-hours prior to completing the TSA testing. Only one ply of tissue is tested. Multi-ply samples are separated into individual plies for testing. The sample is placed in the TSA with the softer (dryer or Yankee) side of the sample facing upward. The sample is secured and the TS7 Softness Values measurements are started via the PC. The PC records, processes and stores all of the data according to standard TSA protocol. The reported TS7 Softness Value is the average of 5 replicates, each one with a new sample.

Fine Crepe Structure To determine the structure of the tissue sheet after creping the crepe structure was characterized using tissue images and the STFI mottling program as described in US Publication No. 2010/0155004 with the following modifications. The STFI mottling program has been written to run with Matlab computer software for computation and programming. A grayscale image is uploaded to the program where an image of the tissue in question had been generated under controlled, low-angle lighting conditions with a video camera, frame grabber and an image acquisition algorithm.

A Leica DFX-300 camera (Leica Microsystems Ltd, Heerbrugg, Switzerland) 420 is mounted on a Polaroid MP-4 Land Camera (Polaroid Resource Center, Cambridge, MA) standard support 422. The support is attached to a Kreonite macro-viewer (Kreonite, Inc., Wichita, KS). An auto-stage, DCI Model HM-1212, is placed on the upper surface of the Kreonite macro-viewer and the sample mounting apparatus was placed atop the auto-stage. The auto-stage is a motorized apparatus known to those skilled in the analytical arts and is commercially available from Design Components Incorporated (Franklin, MA). The auto stage is used to move the sample in order to obtain 15 separate and distinct, non- overlapping images from the specimen. The sample mounting apparatus 424 is placed on the auto macro-stage (DCI 12x12 inch) of an image analysis system controlled by Leica Microsystems QWIN Pro software, under the optical axis of a 60 mm AF Micro Nikon lens (Nikon Corp., Japan) fitted with a 20 mm extension tube. The lens focus is adjusted to provide the maximum magnification and the camera position on the Polaroid MP-4 support is adjusted to provide optimum focus of the tissue edge. The sample is illuminated from beneath the auto-stage using a Chroma Pro 45 (Circle 2, Inc., Tempe, AZ). The Chroma Pro settings are such that the light is 'white' and not filtered in any way to bias the light's spectral output. The Chroma Pro may be connected to a POWERSTAT Variable Auto- transformer, type 3PN117C, which may be purchased from Superior Electric, Co. having an office in Bristol, CT. The auto-transformer is used to adjust the Chroma Pro's illumination level. The resulting image has a pixel resolution of 1024x1024 and represents a 12.5 mmxl2.5 mm field of view. The image analysis system used to perform the PR/EL measurements may be a QWTN Pro (Leica Microsystems, Heerbrugg, Switzerland). The system is controlled and run by Version 3.2.1 of the QWIN Pro software. The image analysis algorithm 'FOE3a' is used to acquire and process grayscale monochrome images using Quantimet User Interactive Programming System (QUIPS) language. Alternatively, the FOE3a program could be used with newer QWIN Pro platforms which run newer versions of the software (e.g. QWIN Pro Version 3.5.1). The image analysis program was previously described in US Publication No. 2010/0155004.

The mottling software analyzes the grayscale variation of the image in both the MD and CD directions by using FFT (Fast Fourier Transform). The FFT is used to develop grayscale images at different wavelength ranges based on the frequency information present within the FFT. The grayscale coefficient-of-variation (% COV) is then calculated from each of the images (e.g. inverse FFT's) corresponding to the wavelengths which were pre-determined by the STFI software. Since these images are generated with low-angle lighting, the tissue surface structure is shown as areas of light and dark, due to shadowing, and consequently the grayscale variation can be related to the tissue surface structure. For each sample, 3 tissue samples are analyzed with 6 images generated for each tissue sample, resulting in a total of 18 images analyzed per sample. Thus, the reported fine crepe structure is an average of the 18 images and is reported as percent COV at a wavelength of 8 to 16 mm.

Tensile

Samples for tensile strength testing are prepared by cutting a 3 inches (76.2 mm) x 5 inches (127 mm) long strip in either the machine direction (MD) or cross-machine direction (CD) orientation using a JDC Precision Sample Cutter (Thwing-Albert Instrument Company, Philadelphia, PA, Model No. JDC 3-10, Ser. No. 37333). The instrument used for measuring tensile strengths is an MTS Systems Sintech 1 IS, Serial No. 6233. The data acquisition software is MTS TestWorks™ for Windows Ver. 4 (MTS Systems Corp., Research Triangle Park, NC). The load cell is selected from either a 50 Newton or 100 Newton maximum, depending on the strength of the sample being tested, such that the majority of peak load values fall between 10 and 90 percent of the load cell's full scale value. The gauge length between jaws is 2+0.04 inches (50.8+1 mm). The jaws are operated using pneumatic-action and are rubber coated. The minimum grip face width is 3 inches (76.2 mm), and the approximate height of a jaw is 0.5 inches (12.7 mm). The crosshead speed is 10+0.4 inches/min (254+1 mm/min), and the break sensitivity is set at 65 percent. The sample is placed in the jaws of the instrument, centered both vertically and horizontally. The test is then started and ends when the specimen breaks. The peak load is recorded as either the "MD tensile strength" or the "CD tensile strength" of the specimen depending on the sample being tested. At least six (6) representative specimens are tested for each product, taken "as is," and the arithmetic average of all individual specimen tests is either the MD or CD tensile strength for the product.

For multiple-ply products tensile testing is done on the number of plies expected in the finished product. For example, 2-ply products are tested two plies at one time and the recorded MD and CD tensile strengths are the strengths of both plies.

Wet Out

Wet Out is measured by first allowing the test product to equilibrate to ambient conditions for at least four hours at 23+/-3.00°C. and 50+/-5 percent relative humidity. Twenty (20) sheets are stacked and cut to a 60 x 60 mm (+3 mm) square using a device capable of cutting to the specified dimensions such as a Hudson Machinery, or equivalent. The square is then fixed in each corner by staples delivered by a standard, commercially available manual office stapler. The staples are placed diagonally across each corner far enough into the sheet so that the staples are completely contacting the tissue sheets, staples should not wrap the corner of the sample. The sample is then held horizontally and approximately 25 mm (1 inch) over a container containing distilled or de-ionized water at 23.0+-3.0°C. The container should be of sufficient size and depth to ensure that the saturated specimen does not contact the sides, bottom of the container, and the top surface of the water at the same time. The container should contain a minimum depth of 51 mm of water to ensure complete saturation of the test specimen and this depth should be maintained throughout the testing. The specimen is then dropped flat onto the water surface and a timing device is started when the specimen contacts the water surface. As soon as the specimen is completely saturated, stop the timing device and record the absorbency wet out time in seconds. HST

Hercules size testing (HST) was done in general accordance with TAPPI method T 530 PM-89, Size Test for Paper with Ink Resistance. Hercules Size Test data was collected on a Model HST tester using white and green calibration tiles and the black disk provided by the manufacturer. A 2 percent Napthol Green N dye diluted with distilled water to 1 percent was used as the dye. All materials are available from Ashland, Inc., Covington, KY.

Six (6) tissue sheets (18 plies for a 3 -ply tissue product, 12 plies for a two-ply product, 6 plies for a single ply product, etc.) form the specimen for testing. All specimens were conditioned for at least 4 hours at 23+l°C and 50+2% relative humidity prior to testing. Specimens are cut to an approximate dimension of 2.5 x 2.5 inches. The specimen (12 plies for a 2-ply tissue product) is placed in the sample holder with the outer surface of the plies facing outward. The specimen is then clamped into the specimen holder. The specimen holder is then positioned in the retaining ring on top of the optical housing. Using the black disk, the instrument zero is calibrated. The black disk is removed and 10+0.5 mm of dye solution is dispensed into the retaining ring and the timer started while placing the black disk back over the specimen. The test time in seconds (sec.) is recorded from the instrument.

EXAMPLES

Inventive sample codes were made using a wet pressed process utilizing a Crescent

Former. Initially, northern softwood kraft (NSWK) pulp was dispersed in a pulper for 30 minutes at 4 percent consistency at about 100°F. The NSWK pulp was then transferred to a dump chest and subsequently diluted to approximately 3 percent consistency. The NSWK pulp was refined at about 1 HP-days/MT. Softwood fibers were then pumped to a machine chest where they were mixed with 2 kg/MT of Kymene® 920A (Ashland Water Technologies, Wilmington, DE) and 1 kg/MT Baystrength 3000 (Kemira, Atlanta, GA) prior to the headbox. The softwood fibers were added to the middle layer in the 3-layer tissue structure. The virgin NSWK fiber content contributed approximately 32 percent of the final sheet weight. Eucalyptus hardwood kraft (EHWK) pulp was dispersed in a pulper for 30 minutes at about 4 percent consistency at about 100°F. The EHWK pulp was then transferred to a dump chest and diluted to about 3 percent consistency. The EHWK pulp fibers were then pumped to a machine chest where they were mixed with 2kg/MT of Kymene® 920A. These fibers were added to dryer and felt layers, as indicated in the Table below.

TABLE 2

The pulp fibers from the machine chests were pumped to the headbox at a consistency of about 0.1 percent. Pulp fibers from each machine chest were sent through separate manifolds in the headbox to create a 3-layered tissue structure. The fibers were deposited onto a felt using a Crescent Former.

The wet sheet, about 10 to 20 percent consistency, was adhered to a Yankee dryer, traveling at about 2000 fpm (610 mpm) through a nip via a pressure roll. The consistency of the wet sheet after the pressure roll nip (post-pressure roll consistency or PPRC) was approximately 40 percent. The wet sheet is adhered to the Yankee dryer due to the creping composition that is applied to the dryer surface. A spray boom situated underneath the Yankee dryer sprayed the creping composition onto the dryer surface. The creping composition comprised a non-fibrous olefin dispersion, sold under the trade name HYPOD 8510 (Dow Chemical Co.). In certain instances Lutensol®A65N was also added to the creping composition. The HYPOD 8510 was prepared at 30 percent solids and delivered at a total addition of about 150 mg/m spray coverage on the Yankee Dryer. In those instances where Lutensol®A65N was added to the creping composition it was added to the composition at 1.0 and 4.8 weight percent, based upon the total weight of the creping composition, such that the total add-on to the Yankee Dryer was about 1.5 mg/m and about 7.5 mg/m .

The sheet was dried to about 98 to 99 percent consistency as it traveled on the Yankee dryer and to the creping blade. The creping blade subsequently scraped the tissue sheet and a portion of the creping composition off the Yankee dryer. The creped tissue basesheet was then wound onto a core traveling at about 1575 fpm (480 mpm) into soft rolls for converting. Two soft rolls of the creped tissue were then rewound, calendered, and plied together so that both creped sides were on the outside of the 2-ply structure. Mechanical crimping on the edges of the structure held the plies together. The plied sheet was then slit on the edges to a standard width of approximately 8.5 inches, and cut to facial tissue length. Tissue samples were conditioned and tested.

TABLE 4

TABLE 5