TW201542149A - Soft and absorbent creped tissue - Google Patents

Abstract

The disclosure provides tissue products having absorbent properties that 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.

Description

Soft and absorbent wrinkled tissue

The present invention provides a soft and absorbent creped tissue product.

Consumers need soft, thin paper, but consumers also want absorbent paper that is absorbent and slowly soaked to protect the consumer's hand during use. The consumer's need poses a problem for tissue makers: the use of additives that impair absorption and barrier properties to increase softness or use additives to increase absorbency and barrier properties at the expense of softness. In an attempt to balance softness and absorbency, tissue makers have used additives in tissue networks that are manufactured by wetting or post-treatment of tissue manufacturing processes. One particular class of additives that have been used by tissue makers are surfactants. For example, U.S. Publication No. 2014/0050889 describes the post-treatment of a tissue web having a surfactant to improve absorbency. On the other hand, U.S. Patent No. 5,730,839 describes the addition of a surfactant during the formation of a tissue web prior to drying. While providing certain benefits, such methods of enhancing absorption properties increase operating costs, increase complexity, and can negatively impact wrinkling, which in turn can reduce softness.

Therefore, it is still necessary to increase without adversely affecting softness. An efficient and simple method of strong absorption properties.

The present inventors have now discovered that surfactants can be added during the creping stage to not only improve the absorption properties, but also to improve the wrinkle structure and increase softness. These absorption properties seek to balance the absorption of the sinus on the one hand and the snivel on the other hand. At the same time, the tissue has a fine wrinkle structure and softness imparted thereby. Accordingly, in one embodiment, the present invention provides a creped tissue product having a moderate degree of moisture resistance (such as a Hercules particle size test (HST) value of from about 2 seconds to about 8 seconds) and subject to The saturation time is controlled (such as a wetting time from about 5 seconds to about 30 seconds).

In other embodiments, the present invention provides a creped tissue product having a Hercules particle size test (HST) value of from about 2 seconds to about 8 seconds and a wetting time of greater than about 5 seconds and less than about 10.0. TS7 value.

In still other specific embodiments, the present invention provides a creped tissue product having a fine wrinkle structure of less than 15% COV measured at a wavelength of from 8 mm to 16 mm, a Hercules particle size of from about 2 seconds to about 8 seconds Test (HST) values and wetting times of from about 5 seconds to about 30 seconds.

In other embodiments, the present invention provides a creped tissue product comprising at least one web having a first side and a second side and a non-fibrous olefin polymer disposed on at least the first side And a non-ionic surfactant creping composition, wherein the tissue product has a Hercules particle size test (HST) value of less than about 10 one TS7 value, from about 2 seconds to about 8 seconds, and from about 5 seconds to about 30 seconds soaking time.

In other embodiments, the present invention provides a method of forming a soft creped tissue web comprising the steps of: forming an aqueous slurry of one of the papermaking fibers; dewatering the aqueous slurry to form a base sheet; a creping composition comprising a surfactant and an olefin polymer applied to a moving creped surface; pressing the base sheet against the creped surface after the creping composition has been applied; and from the creped surface The base sheet is removed.

[definition]

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

As used herein, the term "wet" generally refers to the time required for a tissue sample to fill 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 tension of the web and the tension across the machine direction, as described in the Test Methods section. Ground measurement.

As used herein, the term "slope" has also been referred to as "modulus" means the lines generated by the rendering of the stretching tension to the slope and is TestWorks ^TM procedure described in the tensile strength measured in the test method section MTS The output in . The slope is reported in units of grams per unit sample width (吋) and is measured to be suitable for load-corrected stress points falling between 70 g to 157 g sample yield (0.687 N to 1.540 N) The least square line is divided by the gradient of the sample width.

As used herein, the term "GM slope" generally refers to the machine direction across the square root of the product of the slope of the slope of the machine direction, and is measured as described in the MTS TestWorks ^TM Test Method The tensile strength of the section of the process Output.

As used herein, the term "hardness index" refers to the quotient of the GM slope (in grams) divided by the geometric mean tension (in grams).

As used herein, the term "tissue paper product" means a product made of a base web comprising fibers and includes tissue paper for the bathroom, facial tissue paper, paper towels, industrial wipes, food service wipes, napkins, medical Use pads and other similar products.

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

As used herein, the term "caliing gauge" is based on the TAPPI Test Method 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 annotations for stacking sheets" The representative thickness of a single sheet. The micrometer is used to perform the T411 om-89 Emveco 200-A thin paper caliper tester (Emveco, Inc., Newberg, OR). The micrometer has a load of 2 kPa, a pressure foot area of 2,500 square millimeters, a pressure foot diameter of 56.42 mm, a dwell time of 3 seconds, and a rate of decrease of 0.8 mm per second. The caliper can be expressed in mils (0.001 inch) or micrometers.

As used herein, the term "basic weight" generally refers to the adjusted dry weight per unit area of tissue paper and is typically expressed in grams per square meter (gsm). The basis weight is measured herein using the TAPPI Test Method T-220.

In general, the present invention is directed to creped tissue webs, and the products resulting therefrom. The creped tissue web and product are strong, soft and have desirable absorbent properties such as a wetting time of greater than 5 seconds and an HST value of from about 2 seconds to about 8 seconds. Thus, the tissue of the present invention is somewhat resistant to liquid penetration and relatively slowly saturated. This balance of penetration and saturation provides a tissue that absorbs but protects the hands of the user in use. Surprisingly, these desired absorption properties are achieved without sacrificing softness. Thus, the tissue paper products disclosed herein typically have a TS7 value of less than about 10.0 and more preferably less than about 9.0 (such as from about 8.0 to about 9.0). The tissue also has a finely creped structure measured at a wavelength of 8 mm to 16 mm, such as less than about 15% COV.

The balance of softness and absorbency is typically achieved by the use of a creping composition comprising an olefin polymer and a surfactant. In this manner, the tissue paper product of the present invention is a wet tissue manufacturing apparatus that does not add a processing step such as adding oil, wax, polyoxyxide, fatty alcohol or an emulsion comprising one or more emollients to the web. Or after the processing). In addition, advantageous absorption and wrinkle properties can be achieved without the addition of a sizing agent such as an alkyl sizing agent. Ketone dimer, alkenyl succinic anhydride, rosin size, long chain hydrocarbon anhydride, organic isocyanate, alkylamine formazan chloride, alkylated melamine, styrene acrylic resin, styrene maleic anhydride , styrene acrylate emulsion and hydroxyethylated starch.

Thus, in one embodiment, the tissue web is creped, wherein the creping composition comprises a thermoplastic resin, such as the composition disclosed in U.S. Patent No. 7,807,023, which is incorporated herein by reference. Into this article. The thermoplastic resin can be contained, for example, in an aqueous dispersion prior to application to the creped surface. In a particular embodiment, the creping composition can comprise a non-fibrous olefin polymer. For example, the creping composition can comprise a film forming composition, and the olefin polymer can comprise a copolymer of ethylene and at least one comonomer comprising an olefin such as 1-octene. The creping composition may also contain a dispersing agent such as a carboxylic acid. For example, examples of specific dispersing agents include fatty acids such as oleic acid or stearic acid.

In a particular embodiment, the creping composition can comprise a copolymer of ethylene and octene in combination with an ethylene-acrylic acid copolymer. The ethylene-acrylic acid copolymer is not only a thermoplastic resin but also 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 can exhibit a crystallinity of less than about 50%, such as less than about 20%. The olefin polymer can 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 can also have a relatively small particle size (e.g., from about 0.05 microns to about 5 microns) when included in an aqueous dispersion.

In an alternate embodiment, the creping composition can comprise 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 the olefin polymer, the creping composition preferably also comprises a surfactant. The surfactant may be provided in an amount between about 0.01 weight percent and 3 weight percent, preferably between 0.1 weight percent and 1 weight percent, based on the total amount of the polymer dispersion. The surfactant may comprise a single surfactant or a blend of surfactants. Surfactants contemplated for use in the present invention include any of the known and conventional surfactants, primarily nonionic surfactants and anionic surfactants. Particularly preferred surfactants are nonionic surfactants comprising a compound selected from the group consisting of linear linear alcohols having from about 6 to about 20 carbon atoms; containing from about 6 to about 20 a branched aliphatic alcohol having carbon atoms; a secondary fatty alcohol having from about 6 to about 20 carbon atoms; a branched alcohol condensed with an average of from about 6 to about 15 moles of ethylene oxide per mole of alcohol Ethoxide; a secondary alcohol ethoxylate condensed with an average of from about 6 to about 15 moles of ethylene oxide per mole of alcohol; and mixtures thereof. In a particularly preferred embodiment, the nonionic surfactant component of the stabilizing system may comprise an alkyl phenol, an aliphatic alcohol, an aliphatic carboxylic acid or an acetylenic diol or a block copolymer of ethylene oxide and propylene oxide. The alkoxylation product of the product.

Particularly preferred nonionic surfactants are alkoxylated alkylphenols (such as alkoxylated alkylphenols sold under the trade name Lutensol® (BASF)) and octylphenol ethoxylates (such as in the trademark A octylphenol ethoxylate sold by Triton (Dow Chemical). Other preferred nonionic surfactants are those having from about 7 to 18 carbon atoms and from about 4 to 100 Alkylphenoxy-poly(ethyleneoxy)ethanol of a vinyloxy unit, such as octylphenoxy poly(ethyloxy)ethanol, nonylphenoxy poly(ethyleneoxy) Ethanol and dodecylphenoxy poly(ethyleneoxy)ethanol. Other examples of nonionic surfactants include hexitols (including sorbitan, sorbitol, dehydrated mannitol, and mannitol) anhydrides, polyoxyalkylene derivatives of partially long chain fatty acid esters, such as , sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan tristearate, sorbitan monooleate and sorbitan A polyoxyalkylene derivative of an alcohol trioleate.

In certain preferred embodiments, the creping composition comprises from about 0.5% to about 3.0% by weight of the creping composition and more preferably from about 1.0% to about the weight of the creping composition. 2.5% surfactant. Such surfactant is usually applied to the creping cylinder to from about 0.5mg / m ² to about 5mg additional content / m ² of. In a particularly preferred embodiment, the creping composition comprises an olefin polymer and a nonionic surfactant, and the creped nonionic surfactant comprises from about 1.0% to about 2.5% by weight of the creping composition.

Tissue paper prepared in accordance with the present invention is typically slowly saturated with a wetting time of greater than about 5 seconds, such as from about 5 seconds to about 30 seconds and more preferably from about 5 seconds to about 20 seconds. The tissue is also resistant to liquid permeation and has an HST value of from about 2 seconds to about 8 seconds and more preferably from about 2 seconds to about 6 seconds. This combination of absorbent properties was not found in commercially available tissue as described in Table 1 below.

Accordingly, in certain embodiments, the present invention provides a creped tissue paper product comprising two or more layers, wherein the product has at least about 25 grams per square meter (gsm) and more preferably at least about 30 gsm (such as The basis weight from about 30 gsm to about 40 gsm). At these basic weights, the tissue paper product of the present invention has less than about 1200 g/3" and more preferably less than about 1100 g/3" and even more preferably less than about 1000 g/3" (such as from about 750 g/3" to about 1000 g. Geometric average tension of /3").

The tissue paper product of the present invention typically has a GM slope of 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") under the foregoing basic weight and tensile strength. Thus, tissue paper products typically have a thickness of less than about 20 (such as from about 14 to about 20 and more preferably from about 16 to about 18). Hardness index.

In addition to having improved absorbent properties, the tissue webs and products prepared in accordance with the present invention also have excellent softness and fine wrinkle structure. For example, a tissue web prepared in accordance with the present invention typically has a tissue softness value (also referred to herein as a "TS7 value") that uses an EMTEC tissue softness analyzer as described in the Test Methods section ( "TSA") (Emtec GmbH, Leipzig, Germany) was measured, less than about 10.0 (such as from about 8.0 to about 10.0). Accordingly, in a particularly preferred embodiment, the present invention provides a tissue product having an HST value of from about 2 seconds to about 8 seconds, a wetting time of from about 5 seconds to about 30 seconds, and a TS7 of from about 8.0 to about 10.0. value.

In still other embodiments, the tissue of the present invention not only has desirable absorbent properties (such as an HST value of from about 2 seconds to about 8 seconds and a wetting time of from about 5 seconds to about 30 seconds), but is also soft. A TS7 value of 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, the tissue prepared in accordance with the present invention also has a finely creped structure. In some embodiments, the present invention provides a tissue web having less than 15% COV measured at a wavelength of from 8 mm to 16 mm (such as from about 10% COV to about 15% COV and more preferably about 13 Fine wrinkle structure from % COV to approximately 15% COV). In a particularly preferred embodiment, the present invention provides a tissue paper product having a fine wrinkle structure of less than 15% COV measured at a wavelength of from 8 mm to 16 mm, an HST value of from about 2 seconds to about 8 seconds, and about 5 The soaking time from seconds to about 30 seconds.

In general, any suitable fibrous web can be treated in accordance with the present invention. For example, in one aspect, the base sheet can be a tissue product such as bathroom tissue, facial tissue, paper towels, napkins, and the like. The fibrous product can be made from any suitable type of fiber. Fiber products made in accordance with the present invention may comprise a single layer of fiber product or a multilayer fiber product. For example, in some aspects, a product can comprise two, three or more layers.

Fibers suitable for making fibrous webs comprise any natural or synthetic fibers, including both non-wood fibers and wood or pulp fibers. The pulp fibers can be prepared in high yield or low yield form and can be slurried by any known method, including kraft paper, sulfite, high yield pulping processes, and other known pulping processes. Fibers prepared according to the organic solvent pulping method can also be used, including Fibers and methods disclosed in U.S. Patent Nos. 4,793,898, 4,594,130, and 3,585,104. Useful fibers can also be produced by mashing (illustrated by U.S. Patent No. 5,595,628).

The fibrous web of the present invention may also comprise synthetic fibers. For example, the fibrous web can include up to about 10% (such as up to about 30% or up to about 50% or up to about 70% or more) on a dry weight basis to provide improved benefits. Suitable synthetic fibers include tantalum, polyolefin fibers, polyester fibers, two-component outer sheath-core fibers, multi-component binder fibers, and the like. Synthetic cellulosic fiber types include all varieties and other fibers derived from human silk or chemically modified cellulose.

Chemically treated natural cellulose fibers can be used, for example, mercerized pulp, chemically strengthened or crosslinked fibers or sulfonated fibers. For the good mechanical properties of the fibers formed using the mesh, it is a pity that the fibers are relatively undamaged and mostly unrefined or only slightly refined. Although recycled fibers can be used, the virgin fibers are generally useful for the mechanical properties of the fibers and are free of contaminants. Mercerized fibers, regenerated cellulose fibers, cellulose produced by microorganisms, strontium and other cellulosic materials or cellulose derivatives can be used. Suitable web forming fibers can also include recycled fibers, virgin fibers, or mixtures thereof.

In general, any process capable of forming a mesh can also be used in the present invention. For example, the web forming process of the present invention can utilize wrinkles, wet wrinkles, two wrinkles, re-wrinkling, two re-wrinkling, embossing, wet compaction, air compression, and ventilation. Drying, spunlacing, creping, drying, co-formation, air laying, and other processes known in the art. For spunlaced materials, the percentage of pulp is from about 70% to 85%.

Also suitable for the articles of the present invention are patterned densified or embossed fiber sheets, such as in any of the following U.S. Patent Nos. 4,514,345, 4,528,239, 5,098,522, 5,260,171, and 5,624,790. The disclosure of the fiber flakes, the disclosures of which are incorporated herein by reference. The embossed fiber sheets may have a densified area that has been imprinted against the drum dryer by the embossed fabric and a relatively low densified area corresponding to the deflecting guide in the embossed fabric (for example, The network of "dome" in the fiber sheet, wherein the fiber sheets superimposed on the deflection tube are differentially deflected by the air pressure on the deflection tube to form a lower density pillow-like region or dome in the fiber sheet.

Fiber webs can also be formed without a large amount of internal fiber to fiber bond strength. In this regard, the fiber equipment used to form the base web can be treated with a chemical stripping agent. The release agent can be added to the fiber slurry during the pulping process or can be added directly to the high level slurry tank. Suitable debonding agents useful in the present invention include cationic debonding agents such as fatty dialkyl quaternary ammonium salts, mono fatty alkyl tertiary ammonium salts, primary ammonium salts, imidazoline quaternary salts, polyfluorene oxide, A quaternary salt and an unsaturated fatty alkyl ammonium salt. Other suitable debonding agents are disclosed in U.S. Patent No. 5,529,665, the disclosure of which is incorporated herein by reference.

The fibrous web that can be treated in accordance with the present invention may comprise a single uniform layer of fibers or may comprise a stratified or layered construction. For example, the fibrous web layer may comprise two or three fibrous layers. Each layer can have a different fiber composition. For example, a three-layer high-level headbox typically includes an upper high-level headbox wall and a lower high-level headbox wall. The high level headbox further includes three separate parts a first spacer and a second spacer of the fibrous material layer.

Each of the fiber elastic fibers comprises a dilute aqueous suspension of papermaking fibers. The particular fibers contained in each layer will generally depend on the product being formed and the desired result. For example, the fiber composition of each layer can vary depending on whether a bathroom tissue product, a facial tissue product, or a tissue product is manufactured. For example, in one aspect, the intermediate layer contains southern softwood kraft fiber, either alone or in combination with other fibers, such as high yield fibers. On the other hand, the outer layer contains softwood fibers such as northern softwood kraft paper. In an alternate aspect, the intermediate layer may contain softwood fibers for strength, while the outer layer may comprise hardwood fibers (such as eucalyptus fibers) for perceived softness.

In general, any process capable of forming a base sheet can be used in the present invention. For example, a layer of papermaking material from a high-level headbox is formed by a loop-formed fabric that is suitably supported and driven by a roll. Once retained on the fabric, layer the fiber suspension even if the water passes through the fabric. Water removal is achieved by forming a configuration and by a combination of gravity, centrifugal force and vacuum suction. The formation of a multi-ply paper web is also described and disclosed in U.S. Patent No. 5,129,988, the disclosure of which is incorporated herein by reference.

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 invention, the creping composition can be applied topically to the tissue web as it travels over the fabric, or can be applied to the surface of the dryer drum for transfer to 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, since the mesh is partially carried via one of the rotational paths of the surface of the dryer, heat is imparted to the mesh, from As a result, most of the moisture contained in the mesh is evaporated. The mesh is then removed from the dryer drum by a creping blade. Wrinkling the web as the web is formed further reduces internal bonding within the web and increases softness. On the other hand, application of the creping composition to the web during creping can increase the strength of the web.

In another embodiment, the formed web is transferred to the surface of a rotatable heated dryer drum (which may be a Yankee dryer). In one embodiment, the pressure roller can include a suction pressure roller. In order to adhere the web to the surface of the dryer drum, the creping adhesive can be applied to the surface of the dryer drum by a spray device. The spray device can emit a creping composition made in accordance with the present invention or can emit a conventional creping adhesive. The mesh adheres to the surface of the dryer drum and is then wrinkled from the drum using a creping blade. The dryer drum can be associated with the hood if necessary. The cover can be used to press air onto the mesh or to pass air through the mesh.

In other embodiments, the mesh can adhere to the second dryer drum once it is wrinkled from the dryer drum. The second dryer drum can include, for example, a heated drum surrounded by a cover. The drum can 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 mesh to the second dryer drum, the second spray device can spray the adhesive onto the surface of the dryer drum. For example, in accordance with the present invention, a second spray device can emit a creping composition as described above. The creping composition not only aids in adhering the tissue web to the dryer drum, but also transfers to the surface of the web as the web is wrinkled from the dryer cylinder by the creping blade. Once creped from the second dryer drum, the web can optionally be fed around the cooling drum and cooled before being wound on the spool.

In addition to applying the creping composition during the formation of the fibrous web, the creping composition can also be used in a post forming process. For example, in one aspect, the creping composition can be used during a printing creping process. In particular, once applied locally to the fibrous web, it is found that the creping composition is well suited for adhering the fibrous web to the creped surface, such as in a printing creping operation.

For example, once the fibrous web is formed and dried, the creping composition can be applied to at least one side of the web and at least one side of the web can be subsequently creped. In general, the creping composition can be applied to only one side of the web and only one side of the web can be creped, the creping composition can be applied to both sides of the web and only one of the webs Side creping, or creping compositions can be applied to each side of the web and wrinkles can be applied to each side of the web.

In one embodiment, the creping composition can be added to one side of the web by wrinkling using an in-line or off-line process. The tissue web is applied through a first creping composition application station that includes nip points formed by a smooth rubber press roll and a patterned gravure roll. The gravure roller is in communication with a reservoir containing the first creping composition. The gravure roller 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 of, for example, up to about 200 ° C and more preferably from about 100 ° C to about 150 ° C. In general, the mesh can be heated to a temperature sufficient to dry the web and evaporate any water. It should be understood that in addition to the heated rolls, any suitable heating means may be used to dry the web. For example, in an alternate embodiment, the mesh can be placed in communication with the infrared heater to dry the mesh. In addition to using a heated roller or an infrared heater, other heating devices may include, for example, any combination Suitable convection oven or microwave oven.

The web may be advanced from the heating roller to the second creping composition application table by a take-up roll, the second creping composition application table comprising a transfer roller in contact with the concave roller, the concave roller and the containing The reservoir of the second creping composition is in communication. The second creping composition can 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 varying amounts as desired. Once the second creping composition is applied, the web is adhered to the creping roller by the pressure roller and carried a distance on the surface of the creping cylinder, and then moved from the surface by the action of the creping blade except. The creping blade performs a controlled pattern creping operation on the second side of the tissue web. While the creping composition is applied to each side of the tissue web, only one side of the web is subjected to a creping process. However, it should be understood that in other embodiments, the sides of the mesh may be wrinkled.

Once wrinkled, the tissue web can be pulled through the drying station. The drying station can include any form of heating unit, such as an oven that imparts energy by infrared heat, microwave energy, hot air. The drying station may be necessary in some applications to dry the web and/or cure the creping composition. However, depending on the creping composition selected, in other applications, a drying station may not be required.

The creping composition of the present invention is typically transferred to the web at a high level such that at least about 30% of the creping composition applied to the Yankee dryer is transferred to the web, more preferably at least about 45%. A better transfer is at least about 60%. Generally, from about 45% to about 65% of the creping composition applied to the Yankee dryer is transferred to the web. Therefore, the creping additive transferred to the sheet The amount is a function of the amount of creping additive applied to the Yankee dryer.

The total amount of creping composition applied to the web may range from about 0.1 weight percent to about 10 weight percent based on the total weight of the web, such as from about 0.3 weight percent to about 5 weight percent, such as From about 0.5 weight percent to about 3 weight percent. In order to achieve the desired additive application level, the additional rate of creping composition to the dryer (measured as the mass per unit area (i.e., m ² ) of the dryer surface (i.e., mg)) may be about 50 mg/m. ² to about 300 mg/m ² and still more preferably in the range of about 100 mg/m ² to about 200 mg/m ² . In a particularly preferred embodiment, the creping composition comprises an olefin polymer added at a level of from about 100 mg/m ² to about 200 mg/m ² and added at a level of from about 0.5 mg/m ² to about 5 mg/m ² Nonionic surfactant.

Additionally, the creping composition is applied to the paper web to cover from about 15% to about 100% of the surface area of the web. More specifically, in most applications, the creping composition will cover from about 20% to about 60% of the surface area of the web.

In one aspect, a fibrous web made in accordance with the present invention can be incorporated into a multilayer product. For example, in one aspect, a fibrous web made in accordance with the present invention can be attached to one or more other fibrous webs for forming a wiping product having the desired characteristics. Other webs laminated to the fibrous web of the present invention can be, for example, wet creped webs, calendered webs, embossed webs, air dried webs, creped air drying webs , non-wrinkled air-dried mesh, air-spacing mesh and the like.

In one aspect, when incorporating a fibrous web made in accordance with the present invention into a multilayer product, it may be desirable to apply only the creping composition to one side of the fibrous web and thereafter to cause the web to pass through Treatment side wrinkles. Then make The wrinkled side of the web is used to form the outer surface of the multilayer product. In another aspect, the untreated and wrinkle-free side of the web is attached to one or more layers by any suitable means.

[testing method] [Thin Paper Softness (TSA)]

Sample softness was analyzed using an EMTEC Tissue Softness Analyzer ("TSA") (Emtec Electronic GmbH, Leipzig, Germany). The TSA contains a rotor with a vertical blade that rotates on a specimen to which a defined contact pressure is applied. The contact between the vertical blade and the sample generates vibration, and the vibration is sensed by the vibration sensor. The sensor then transmits the signal to the PC for processing and display. The signal is shown as a frequency spectrum. A frequency analysis in the range of approximately 200 Hz to 1000 Hz represents the surface smoothness or texture of the sample. High amplitude peaks are associated with rougher surfaces. Another peak in the frequency range between 6 kHz and 7 kHz indicates the softness of the sample. The peak in the frequency range between 6 KHz and 7 KHz is referred to herein as the TS7 softness value and is expressed as dB V2 rms. The lower the amplitude of the peak appearing between 6 KHz and 7 KHz, the softer the sample.

Test samples were prepared by cutting a circular sample having a diameter of 112.8 mm. All samples were allowed to equilibrate for at least 24 hours under TAPPI standard temperature and humidity conditions prior to completion of the TSA test. Test only one layer of tissue. The multilayer samples were separated into individual layers for testing. Samples were placed in the TSA with the softer (dryer or Yankee) side up of the sample. The sample is tightened and the TS7 softness value measurement is started via the PC. The PC records, processes and stores all data in accordance with the standard TSA agreement. Reported TS7 Soft The softness value is the average of 5 replicates, each replica has a new sample.

[fine wrinkle structure]

In order to determine the structure of the tissue sheet after creping, the crepe structure was characterized using a tissue image and an STFI ink spot program having the following modifications as described in US Publication No. 2010/0155004. The STFI ink spot program has been written to be executed with Matlab computer software for calculation and stylization. The grayscale image is uploaded to the program, where the image of the tissue in question has been generated using a video camera, frame grabber, and image acquisition algorithm under controlled, low angle illumination conditions.

A Leica DFX-300 camera (Leica Microsystems Ltd, Heerbrugg, Switzerland) 420 was mounted on a Polaroid MP-4 Land Camera (Camola, MA) standard support 422. The support was attached to a Kreonite giant viewer (Kreonite, Inc., Wichita, KS). The automatic stage (DCI model HM-1212) is placed on the upper surface of the Kreonite giant viewer, and the sample mounting equipment is placed on top of the automatic stage. The automated stage is a motorized device known to the analytical artisan and is commercially available from Design Components Incorporated (Franklin, MA). The automatic stage is used to move the sample to obtain 15 separate and distinct non-overlapping images from the sample. The sample mounting device device 424 is placed under the optical axis of a 60 mm AF Micro Nikon lens (Nikon Corp., Japan) equipped with a 20 mm extension tube and placed in an automatic mega class (DCI 12) of an image analysis system controlled by Lycra Microsystems QWIN Pro software. ×12吋). The lens focus is adjusted to provide maximum magnification, and the camera position on the Polaroid MP-4 support is adjusted to provide a thin paper edge The best focus of the edge. The samples were illuminated from the sub-automated level using Chroma Pro 45 (Circle 2, Inc., Tempe, AZ). Chroma Pro is set such that the light system is "white" and is not filtered anyway to bias the spectral output of the light. The Chroma Pro can be connected to a POWERSTAT variable autotransformer (model 3PN117C), which is available from Bristol Electric, Co., of Bristol, CT. The automatic transformer is used to adjust the illumination level of the Chroma Pro. The resulting image has a pixel resolution of 1024 x 1024 and represents a 12.5 mm x 12.5 mm field of view.

The image analysis system used to perform PR/EL measurements can be QWIN Pro (Leica Microsystems, Heerbrugg, Switzerland). The system is controlled and executed by the 3.2.1 version of the QWIN Pro software. The image analysis algorithm "FOE3a" is used to acquire and process grayscale monochrome images using the Quantitant User Interactive Programming System (QUIPS). Alternatively, the FOE3a program can be used by newer QWIN Pro platforms that implement newer versions of the software (eg, QWIN Pro version 3.5.1). This image analysis program was previously described in U.S. Publication No. 2010/0155004.

The ink spot software analyzes the gradation change of the image in both the MD and CD directions by using Fast Fourier Transform (FFT). The FFT is used to visualize grayscale images at different wavelength ranges based on frequency information present within the FFT. The gray scale coefficient of variation (% COV) is then calculated (e.g., inverse FFT) from each of the images corresponding to the wavelengths predetermined by the STFI software. Since these images are produced by low-angle illumination, the surface structure of the tissue is shown as a bright and dark area due to the shadow, and thus the grayscale change can be correlated with the surface of the tissue. Structure related. For each sample, 3 tissue samples were analyzed with 6 images generated for each tissue sample, resulting in a total of 18 images per sample analysis. Thus, the reported fine wrinkle structure is the average of the 18 images and is reported as a percentage of COV at wavelengths from 8 mm to 16 mm.

[tension]

The samples used for the tensile strength test were determined by the JDC Precision Sample Cutting Machine (Thwing-Instrument Company, Philadelphia, PA, Model JDC3-10, No. 37333) in the machine direction (MD) or across the machine direction (CD). Prepared by cutting a strip of 3 inches (76.2 mm) x 5 inches (127 mm) upward. The apparatus for measuring the tensile strength is MTS system Sintech 11S, No. 6233. Data acquisition software system for Windows version MTS 4 of ^{TestWorks TM (MTS Systems Corp., Triangle} Park, NC). The dynamometer is selected from 50 Newtons or 100 Newtons (maximum) depending on the strength of the sample being tested, such that most of the peak load value falls between 10% and 90% of the full scale value of the dynamometer. The gauge length between the jaws is 2 ± 0.04 吋 (50.8 ± 1 mm). The jaws are operated using pneumatic action and are coated with rubber. The minimum gripping tooth width is 3 吋 (76.2 mm) and the approximate height of the jaws is 0.5 吋 (12.7 mm). The crosshead speed was 10 ± 0.4 吋 / min (254 ± 1 mm / min), and the damage sensitivity was set to 65%. The sample is placed in the jaws of the appliance in a vertical and horizontally centered manner. The test then begins and ends when the sample is destroyed. The peak load is recorded as the "MD tensile strength" or "CD tensile strength" of the sample depending on the positive test sample. At least six (6) representative samples ("as is") are tested for each product, and the arithmetic mean of all individual sample tests is the MD or CD tensile strength of the product.

For multilayer products, the tensile test is performed on several layers expected in the finished product. For example, a 2-layer product will be tested in two layers at a time, and the recorded MD and CD tensile strengths are the strength of the two layers.

[wet]

Wetting 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% relative humidity. Twenty sheets (20) of sheets are stacked and cut into 60 mm x 60 mm (± 3 mm) squares using a device capable of cutting to a specified size, such as a Hudson machine or equivalent. The staple fibers delivered by the standard commercially available staple fiber cutter are then fixed in square at each corner. The staple fibers are placed far enough into the sheet across the corners on the diagonal so that the staple fibers are in full contact with the tissue sheet and the staple fibers should not wrap around the corners of the sample. The sample was then held horizontally approximately 25 mm (1 Torr) above the container containing distilled or deionized water at 23.0 + -3.0 °C. The container should be of sufficient size and depth to ensure that the saturated sample does not simultaneously contact the sides, bottom and top surface of the container. The container should contain water with a minimum depth of 51 mm to ensure complete saturation of the test specimen and this depth should be maintained during the test. The sample is then placed flat on the surface of the water and the timing device is activated when the sample contacts the surface of the water. Once the sample is fully saturated, the timing device is stopped and the absorption soak time is recorded in seconds.

[HST]

The Hercules particle size test (HST) is generally carried out according to the TAPPI method T 530 PM-89 (particle size test for paper having ink repellency). Hera Kellers particle size test data was collected on a modeled HST tester using white and green calibration blocks and black discs supplied by the manufacturer. A 2% naphthol green N dye diluted to 1% with distilled water was used as the dye. All materials are available from Ashland, Inc. (Covington, KY).

Six (6) tissue sheets (18 layers for 3-layer tissue products, 12 layers for two-layer products, 6 layers for single-layer products, etc.) were used to form samples for testing. All samples were conditioned at 23 ± 1 ° C and 50 ± 2% relative humidity for at least 4 hours prior to testing. The sample was cut to an approximate size of 2.5 吋 x 2.5 。. A sample (12 layers for a 2-layer tissue product) was placed in the sample holder with the outer surface of the layers facing outward. The sample is then clamped into the sample holder. The sample holder is then positioned over the optical housing over the buckle. Use a black disc to pass the calibration tool zero. The black disc was removed and a 10 ± 0.5 mm dye solution was dispensed into the buckle and the timer was started when the black disc was placed back over the specimen. The test time in seconds is recorded from the appliance.

[Example]

The sample code of the present invention is produced using a wet pressing process using a crescent forming device. Initially, Northern Softwood Kraft (NSWK) pulp was dispersed in a beater at about 100 °F for 4 minutes at a consistency of 4%. The NSWK pulp was then transferred to a discharge tank and subsequently diluted to approximately 3% consistency. The NSWK pulp was refined at about 1 HPD/MT. The cork fibers are then pumped to the pulper pool where the softwood fibers are in contact with 2 kg/MT of Kymene® 920A (Ashland Water Technologies, DE) and 1 kg/MT of Baystrength 3000 before entering the high-level headbox. (Kemira, Atlanta, GA) mixed. Will be soft Wood fibers were added to the middle layer of the 3-layer tissue structure. The original NSWK fiber content contributes approximately 32% of the final sheet weight.

Eucalyptus hardwood kraft (EHWK, Eucalyptus hardwood kraft) pulp was dispersed in a beater at about 100 °F for about 30 minutes at about 4% consistency. The EHWK pulp was then transferred to a discharge tank and diluted to a consistency of about 3%. The EHWK pulp fibers are then pumped to a paper machine pulp tank where they are mixed with 2 kg/MT of Kymene® 920A. These fibers were added to the dryer and felt layers as indicated in the table below.

The pulp fibers from the pulper pool are pumped to the high level pulp box at a consistency of about 0.1%. The pulp fibers from each pulper pool are sent via separate manifolds in the high level headbox to create a 3-layer tissue structure. The fibers are deposited onto the felt using a crescent forming machine.

A wet sheet of about 10% to 20% consistency is adhered to the Yankee dryer to travel through the nip point at about 2000 fpm (610 mpm) via a press roll. The consistency of the wetted sheet after the pinch nip point (post-roller consistency or PPRC) was approximately 40%. The wetted sheet adheres to the Yankee dryer due to the creping composition applied to the dryer surface. A spray bar located under the Yanji dryer sprays the creping composition onto the dryer surface. The creping composition comprises a non-fibrous olefin dispersion sold under the trade name HYPOD 8510 (Dow Chemical Co.). In some cases, Lutensol® A65N is also added to the creping composition. HYPOD 8510 was prepared as a 30% solids and delivered on a Yankee dryer at a total addition of about 150 mg/m ² spray coverage. In the case where Lutensol® A65N is added to the creping composition, the material is added to the composition at 1.0 and 4.8 weight percent based on the total weight of the creping composition such that the total addition to the Yankee dryer is About 1.5 mg/m ² and about 7.5 mg/m ² .

When the sheet travels on the Yankee dryer and reaches the creping blade, the sheet is dried to a consistency of about 98% to 99%. The creping blade then scrapes off a portion of the tissue sheet and creping composition from the Yankee dryer. The creped tissue base sheet was then wound onto a core running at about 1575 fpm (480 mpm) to become a soft roll for conversion. The two soft rolls of creped tissue are then re-wound, calendered and laminated together such that the two creped sides are on the outer side of the 2-layer structure. Mechanical crimping on the edges of the structure holds the layers together. The laminated sheet is then slit on the edge to a standard width of approximately 8.5 inches and cut to the face tissue length. Adjust and test thin paper samples.

Claims (20)

A creped tissue product having a Hercules particle size test (HST) value of from about 2 seconds to about 8 seconds and a wetting time of from about 5 seconds to about 30 seconds and a TS7 value of less than about 10.0. A creped tissue product as claimed in claim 1 which has an HST value of from 2 seconds to about 5 seconds. A creped tissue product as claimed in claim 1 which has a wetting time of from about 5 seconds to about 20 seconds. The creped tissue paper product of claim 1, wherein the tissue product further comprises a nonionic surfactant. A creped tissue product according to claim 4, wherein the surfactant comprises a nonionic surfactant selected from the group consisting of alkoxylated alkylphenols and octylphenol ethoxylates. A creped tissue product according to claim 4, wherein the nonionic surfactant comprises from about 0.001 weight percent to about 0.05 weight percent based on the dry weight of the tissue product. A creped tissue product as claimed in claim 1 having a coefficient of variation (COV) of less than 15% measured at a wavelength of from 8 mm to 16 mm. Coefficient-of-variation) fine wrinkle structure. A creped tissue product as claimed in claim 1 which has a hardness index of less than about 18. A creped tissue product according to claim 8 wherein the hardness index is from about 16 to about 18. A creped tissue product according to claim 1 wherein the TS7 value is less than about 9.0. A creped tissue product comprising at least one web having a first side and a second side and a non-fibrous olefin polymer and a nonionic surfactant disposed on at least the first side A creping composition wherein the tissue product has a TS7 value of less than about 10.0, a Hercules particle size test (HST) value of from about 2 seconds to about 8 seconds, and a wetting time of greater than about 5 seconds. A creped tissue web as claimed in claim 11 having a fine crepe structure of less than 15% COV measured at a wavelength from 8 mm to 16 mm. A creped tissue web of claim 11, wherein the tissue product has a geometric average tension of from about 800 g/3" to about 1100 g/3". A creped tissue product according to claim 11 which has an HST value of from 2 seconds to about 5 seconds. The creped tissue product of claim 11, wherein the surfactant comprises a nonionic surfactant selected from the group consisting of alkoxylated alkylphenols and octylphenol ethoxylates. The creped tissue web of claim 11, wherein the olefin polymer comprises an alpha olefin copolymer of ethylene and at least one comonomer selected from the group consisting of C _4-20 linear, branched Or a cyclic diene, vinyl acetate, and a compound represented by the formula H ₂ C=CHR, wherein R is a C _1-20 linear, branched or cyclic alkyl group or a C _6-20 aryl group, or the alpha olefin polymer a copolymer comprising propylene glycol and at least one comonomer selected from the group consisting of ethylene, a C _4-20 linear, branched or cyclic diene, and a compound represented by the formula H ₂ C=CHR, wherein R is C _1-20 linear, branched or cyclic alkyl or C _6-20 aryl. A method of forming a soft creped tissue web comprising the steps of: a. forming an aqueous slurry of papermaking fibers; b. dehydrating the aqueous slurry to form a base sheet; c. comprising an interface a crease composition of the active agent and the olefin polymer is applied to a moving creped surface; d. pressing the base sheet against the creped surface after the creping composition has been applied; and e. removing the base sheet from the creped surface. The method of claim 17, wherein the surfactant comprises a nonionic surfactant selected from the group consisting of alkoxylated alkylphenols and octylphenol ethoxylates, and the olefin polymer comprises An alpha olefin copolymer of ethylene and at least one comonomer selected from the group consisting of C _4-20 linear, branched or cyclic diene, vinyl acetate, and a compound represented by the formula H ₂ C=CHR, Wherein R is a C _1-20 linear, branched or cyclic alkyl group or a C _6-20 aryl group, or the alpha olefin polymer comprises a copolymer of propylene glycol and at least one comonomer selected from the group consisting of: Ethylene, C _4-20 linear, branched or cyclic diene and compounds represented by the formula H ₂ C=CHR wherein R is a C _1-20 linear, branched or cyclic alkyl group or a C _6-20 aryl group. The method of claim 18, wherein the nonionic surfactant comprises from about 0.5% to about 2.0% by weight of the creping composition. The method of claim 19, wherein the nonionic surfactant is applied at an additional level of from about 0.5 mg/m ² to about 5.0 mg/m ² .