RU2430709C2 - Wipe product - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: wipe product relates to absorbent paper products. A wipe product represents a wipe sheet having a first side and a second side. The wipe sheet contains cellulose fibres in an amount at least 50 wt %, and an additional composition containing polymer. The additional composition is present at least on the first side of the wipe sheet. The wipe product has extensionality exceeding 3 cm³/g, a fluffiness test value less than approximately 3 mg, and the first side of the wipe sheet has a stick-slip value more than approximately 0.01. The additional composition contains a non-fibrous olefin polymer, ethylene carboxylic acid copolymer or their mixture. The additional composition can be included in a wipe cloth by means of fibre combination to be used for cloth formation. Alternatively, the additional composition can be superficially applied on the formed cloth.

EFFECT: better quality of the wipe product.

20 cl, 42 dwg, 18 tbl, 7 ex

Description

BACKGROUND

Absorbent paper products such as paper towels, facial wipes, toilet paper and other similar products are designed to have several important properties. For example, products should have good bulkiness, create a feeling of softness and be highly absorbent. The product must also have good strength and be tear resistant even when wet. Unfortunately, it is very difficult to produce paper products of high strength, which are also soft and well absorbent. Usually, during the stage at which one product property is improved, other product characteristics, on the contrary, deteriorate.

For example, softness is usually enhanced by reducing or decreasing the cellulosic fiber compounds in the paper product. In the past, for example, paper webs were subjected to various types of creping processes to increase softness. In one embodiment, for example, the wet paper web was pressed onto a heated rotating drum, such as a Yankee tumble dryer, and creped from the surface of the drum after sufficient drying. Creping the web increases the softness and bulkiness of the web by pressing the web and reducing fiber bonds.

In another embodiment, the paper web was subjected to a creped printing process in which a bonding agent was applied to the surface of a dry web to adhere the web to the creping drum. For example, a printing creping process is disclosed in US Pat. No. 3,879,257 to Gentile et al., Which is incorporated herein by reference in its entirety. In the patent of Gentile et al., A process is described in which a binder material is applied with a thin defined pattern on one side of a fibrous web. The canvas is then adhesively attached to a heated creping surface and creped from the surface.

Binder material is applied to the opposite side of the web and the web is likewise creped. Using the process described in Gentile et al., It produces tissue products having exceptional bulkiness, softness and good absorbency. The surface areas of the web also provide excellent strength, abrasion resistance and dry wipe properties.

Although the creping processes described above have been quite successful in improving the softness of paper webs, in some applications creping the webs can cause a greater degree of hairiness and confusion during use. Therefore, there is a need for a manufacturing process for paper products that produce reduced levels of hairiness during use.

SUMMARY OF THE INVENTION

In general, the present invention is directed to sheet type products having improved properties due to the presence of an additive composition. For example, incorporating the additive composition in a leaf type product can significantly improve the hairiness properties of the product. The sheet type product may be, for example, toilet paper, face wipes, paper towels, industrial wipes, pre-wetted wipes, and the like. The product may contain one layer or may contain many layers. The additive composition can be included in the sheet product in order to also improve the strength of the product without significantly affecting the softness or adhesion properties of the product in a negative way. Indeed, the additive composition can improve softness along with increased strength. The additive composition may contain, for example, an aqueous dispersion containing a thermoplastic polymer. In one embodiment, the additive composition is applied locally to the web, as in a creping operation.

The additive composition may comprise a non-fibrous olefin polymer. The additive composition, for example, may contain a film-forming composition, and the olefin polymer may contain an ethylene copolymer and at least one comonomer containing an alkene, such as 1-octene. The additive composition may also contain a dispersant, such as a carboxylic acid. Examples of specific dispersing agents, for example, include fatty acids such as oleic acid or stearic acid.

In one specific embodiment, the additive composition may comprise a copolymer of ethylene and octene in combination with a copolymer of ethylene and acrylic acid. A copolymer of ethylene and acrylic acid is not only a thermoplastic polymer, but can also serve as a dispersing agent. A copolymer of ethylene and octene may be present in combination with a copolymer of ethylene and acrylic acid 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 crystallinity of less than about 50%, such as less than about 20%. The olefin polymer may also have a melting 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 0.1 microns to about 5 microns, when contained in an aqueous dispersion.

In an alternative embodiment, the additive composition may comprise a copolymer of ethylene and acrylic acid. A copolymer of ethylene and acrylic acid may be present in combination with a dispersing agent, such as a fatty acid.

In one embodiment, the additive composition may be applied on top of one side or both sides of the paper web. It has been found that when applied to a paper web, the additive composition may form an intermittent but interconnected film depending on the amount applied to the web. Thus, the additive composition increases the strength of the web without significantly affecting the ability of the web to absorb liquids. For example, the intermittent film that forms includes holes that allow liquids to be absorbed by the paper web.

In other embodiments, the additive composition may be applied to the web in relatively small amounts, so that the additive composition forms separate treated areas on the surface of the web. Even with such low amounts, however, the additive composition can still improve one or more properties of the web.

Another advantage is that the additive composition does not substantially penetrate the paper web upon application. For example, the additive composition penetrates into the paper web in an amount of less than about 30% of the thickness of the web, for example as less than about 20%, for example about 10% of the thickness of the web. Remaining mainly on the surface of the web, the additive composition does not affect the ability of the web to absorb liquid. In addition, the additive composition essentially does not increase the rigidity of the web and, as described above, does not cause problems with sticking.

In one embodiment, the additive composition may be applied to one side of the tissue web to adhere the tissue web to the creping drum and for securing the tissue web from the surface of the drum. In this embodiment, for example, the additive composition may be applied to one side of the tissue web in accordance with the pattern. The pattern may comprise, for example, a pattern of individual shapes, a mesh pattern, or a combination thereof. In order to apply the additive composition to the tissue web, the additive composition can be printed onto the tissue web in accordance with the pattern. For example, in one embodiment, a rotogravure printer may be used.

The additive composition may be applied to one side of the tissue web in an amount of from about 0.1 wt.% To about 30 wt.%. In some embodiments, after applying the additive composition to the web, the web can be dried at a temperature in the range equal to or greater than the melting point of the base polymer in the additive composition. When applied, the additive composition remains essentially on the surface of the tissue web to increase strength without affecting the absorbent properties of the web. For example, when applied to a tissue web, the additive composition can penetrate into the tissue web less than about 10% of the thickness of the tissue web, for example less than about 5% of the thickness of the web. The additive composition may form an intermittent film on the surface of the tissue web to provide strength, while also providing untreated areas in which liquids can be quickly absorbed by the web.

When the tissue web is adhesively attached to the creping drum, the creping drum may be heated if desired. For example, the creping surface may be heated to a temperature of from about 80 ° C to about 200 ° C, for example from about 100 ° C to about 150 ° C. The additive composition may be applied only to one side of the tissue web, or may be applied to both sides of the cloth in accordance with the same or different patterns. When applied to both sides of the web, both sides of the web can be creped from a creping drum or only one side of the web can be creped.

A tissue web treated with the additive composition may, in one embodiment, comprise a non-creped fabric dried in a through air stream before applying the additive composition. When creped from a creping surface, the web may have a relatively high bulk, such as exceeding 10 cc / g. The tissue product can be used as a single layer product or it can be included in a multilayer product.

As described above, the additive composition can improve various properties of the base sheet. For example, the additive composition gives the base sheet a sensation of wetness with lotion and softness. One test in which one aspect of softness was measured is called a friction jump test. During the friction test, the slide was pulled along the surface of the base sheet, while measuring the resistance force. A higher number of jumps during friction means a lotion-treated surface with less drag. Tissue sheets processed in accordance with the present description, for example, may have jumps during friction on one side of more than -0.01, for example, from about -0.006 to about 0.7, such as from about 0 to about 0.7 .

In addition, the properties of the base sheet are improved without creating any significant adhesion problems. For example, tissue products processed in accordance with the present description, when stacked together, may have adhesion of sheets of less than 15 gram-force, for example, less than about 10 gram-force (gf). For example, in specific embodiments, stacked products may have sheets stick together in less than about 5 gs, such as even less than about 2 gs.

The main fabric processed in accordance with the present description, also show reduced properties of hairiness. For example, applying the additive composition to one side of the base sheet can significantly reduce the amount of fluff or waste that can be obtained from the base sheet when used. For example, base sheets containing cellulosic fibers may have a test hairiness of less than about 3 mg, such as less than about 2.5 mg, such as less than about 2 mg, such as less than about 1.5 mg, or even less about 1 mg. The above-described test hairiness values can be obtained for base sheets, for example, containing cellulosic fibers in an amount of from about 50 to about 100 wt.%, Such as above 70 wt.%, Such as above about 80 wt.%, Such as above 90 wt.%.

The base sheets processed in accordance with the present description may be made entirely of cellulose fibers, such as pulp fibers, or may be made of a mixture of fibers. For example, base sheets may contain cellulosic fibers in combination with man-made fibers.

The base sheets that can be processed in accordance with the present description include tissue sheets laid in a wet state. In other embodiments, however, the base sheet may comprise an air laid web, a hydraulically entangled web, a co-molded web, and the like.

Other features and objects of the present invention are described in more detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and explanatory description of the present invention, including the best options for its implementation for a person skilled in the art, is described in more detail in the rest of the description, including links to the accompanying drawings, in which:

1 is a diagram of a tissue forming apparatus showing the formation of a multilayer tissue web having multiple layers in accordance with the present invention;

FIG. 2 is a schematic diagram of one embodiment of a process for forming uncreped air-dried tissue webs for use in the present description; FIG.

Figure 3 is a schematic diagram of one embodiment of a process for forming creped wet-pressed tissue sheets for use in the present description;

4 is a schematic diagram of one embodiment of a process for applying additional compositions to each side of a tissue web and creping one side of the web in accordance with the present description;

Figure 5 is a top view of one embodiment of a pattern that is used to apply additional compositions to tissue webs made in accordance with the present invention;

6 is another embodiment of a pattern that is used to apply additional compositions to tissue webs in accordance with the present invention;

7 is a top view of another alternative embodiment of the pattern, which is used for applying additional compositions on tissue sheets in accordance with the present description;

Fig. 8 is a schematic diagram of an alternative embodiment of a process for applying an additive composition to one side of a tissue web and creping one side of the tissue in accordance with the present invention;

Figures 9-27 and 28-34 are the results obtained in the Examples, as described below;

FIG. 27 is a diagram showing equipment used to perform friction jump tests; FIG.

Fig. 35 is a schematic diagram of another embodiment of a process for forming creped tissue sheets in accordance with the present invention;

Fig. 36 is a schematic diagram of another embodiment of a process for applying an additive composition to one side of a tissue web and creping one side of the web in accordance with the present description;

Fig. 37 is a schematic diagram of another embodiment of a process for applying an additive composition to one side of a tissue web and creping one side of the web in accordance with the present invention;

Fig. 38 is a cross-sectional view of the preparation of samples used to perform the sticking test;

Fig, 40 and 41 are the results obtained in Example No. 6 below, and

Fig. 42 is a perspective view of a device that can be used to perform a hairiness test in accordance with the present invention.

The reuse of the reference numbers in the present description and in the drawings is intended to mean the same or similar features or elements of the present invention.

DETAILED DESCRIPTION

The person skilled in the art should understand that the present description is only a description of the preferred embodiments and is not intended to limit the broadest objects of the present invention.

In general, the present description is directed to incorporating an additive composition into a sheet type product, such as a tissue web, in order to improve various properties. For example, incorporating the additive composition into a tissue web can reduce the amount of fluff produced by the web during use. The strength of the web can also be increased without significantly affecting the property of sensing softness of the web. Indeed, softness can be enhanced in some applications. The additive composition may contain a polyolefin dispersion. For example, a polyolefin dispersion may contain polymer particles having a relatively small size, such as less than about 5 microns, in an aqueous medium when applied to or incorporated into a tissue web. When dried, however, the polymer particles are generally indistinguishable. For example, in one embodiment, the additive composition may comprise a film-forming composition that forms an intermittent film and / or forms separate treated areas on a base sheet. In some embodiments, the polyolefin dispersion may also contain a dispersing agent.

As will be described in more detail below, the additive composition may be included in the tissue using various technologies and during various stages of the production of tissue products. For example, in one embodiment, the additive composition may be combined with an aqueous suspension of fibers that is used to form a tissue web. In an alternative embodiment, the additive composition may be applied to a dry pulp sheet that is used to form a tissue web. In an alternative embodiment, the additive composition may be applied to a dry pulp sheet, which is used to form an aqueous suspension of fibers. In yet another embodiment, the additive composition may be locally applied to the tissue web when the tissue web is wet or after the tissue web has been dried. For example, in one embodiment, the additive composition may be applied locally to a tissue web. For example, the additive composition may be applied to a tissue web during a creping operation. In particular, it was found that the additive composition is well suited for adhering the tissue web to the creping surface in the creping process.

It has been found that the use of an additive composition containing a polyolefin dispersion provides various advantages and advantages depending on the particular embodiment. For example, it was found that the additive composition improves the geometric mean value of tensile strength and geometric mean value of the energy of the gap consumed by the processed tissue sheets compared to untreated paintings. In addition, the strength properties described above can be improved without significantly adversely affecting the stiffness of tissue webs with respect to untreated webs and with respect to tissue webs treated with a silicone composition, as has been generally accepted in the past. Thus, tissue webs made in accordance with the present description may have a perceived softness that is similar to or equivalent to tissue webs treated with a silicone composition. Napkin cloths made in accordance with the present description, however, can have significantly improved strength properties at the same tangible levels of softness.

Improving the strength properties is also comparable to prior art tissue sheets processed with a binder material such as an ethylene vinyl acetate copolymer. The problem with sheet adhesion, however, which is the tendency of adjacent sheets to adhere to each other, is greatly reduced when tissue webs are made in accordance with the present description compared to webs treated with an additional ethylene vinyl acetate copolymer composition as has been done in the past.

In addition, it was found that the additive composition, when included in the base sheet containing cellulosic fibers, can significantly improve the sheet hairiness properties. More specifically, the inclusion of the additive composition in the base sheet reduces the tendency to hairiness and rolling caused during use of the product. For example, base sheets made as described herein may have a hairiness test value of less than about 3 mg, such as less than about 2.5 mg, such as less than about 2 mg, such as less than about 1.5 mg, such as even less than about 1 mg.

The above advantages and advantages can be obtained by incorporating the additive composition into the tissue web at almost any point in the production process of the web. The additive composition generally comprises an aqueous dispersion comprising at least one thermoplastic polymer, water, and optionally at least one dispersing agent. A thermoplastic polymer is present in the dispersion in the form of particles of a relatively small size. For example, the average volumetric particle size of the polymer may be less than about 5 microns. The actual particle size may depend on various factors, including the thermoplastic polymer that is present in the dispersion. Thus, the average volumetric particle size can be from about 0.05 microns to about 5 microns, such as less than about 4 microns, such as less than about 3 microns, such as less than about 2 microns, such as less than about 1 micron. Particle sizes can be measured on a Coulter LS230 scattered light particle size analyzer or other suitable device. When present in an aqueous dispersion and when present in a tissue web, the thermoplastic polymer is usually in a non-fibrous form.

The particle size distribution of the polymer in the dispersion may be less than or equal to about 2.0, such as less than 1.9, 1.7 or 1.5.

Examples of aqueous dispersions that may be included in the additive composition of the present invention are described, for example, in US Patent Application Publication No. 2005/0100754, US Patent Application Publication No. 2005/0192365, in International Publication WO 2005/021638 and in International Publication WO 2005/021622, all of which are incorporated herein by reference.

In one embodiment, the additive composition may comprise a film-forming composition capable of forming a film on the surface of the tissue web. For example, when applied locally to a tissue sheet, the additive composition may form an intermittent but interconnected film. In other words, the additive composition forms a mutually connected polymer network on the surface of the tissue web. The film or polymer network, however, is intermittent in the sense that various openings are contained in the film. The size of the holes may vary depending on the amount of the additive composition that is applied to the web and the method by which the additive composition is applied. Particularly preferably, the openings allow liquid to be absorbed through the intermittent film and into the tissue. In this regard, the presence of the additive composition does not significantly affect the liquid distribution properties of the tissue web.

In other embodiments, when the additive composition is added in relatively small amounts to the base web, the additive composition does not form a interconnected grid, but instead appears on the main sheet as treated separate areas. Even with relatively low amounts, however, the additive composition can still improve at least one property of the base sheet. For example, the feel of the base sheet and its hairiness properties can be improved even when the amounts are less than about 2.5 wt.%, Such as less than 2 wt.%, Such as less than 1.5 wt.%, Such as less than 1 wt.%, such as less than 0.5 wt.%.

In addition, in some embodiments, the additive composition remains mainly on the surface of the tissue web and does not penetrate the web immediately upon application. Thus, the intermittent film not only allows the tissue to absorb liquids that come into contact with the surface, but also does not significantly affect the ability of the tissue to absorb relatively large amounts of liquid. Thus, the additive composition does not have a significant effect on the absorption properties of the web fluid, while increasing the strength of the web without a significant negative effect on the stiffness of the web.

The thickness of the additive composition, when present on the surface of the base sheet, may vary depending on the ingredients of the additive composition and the amount applied. In general, for example, the thickness may vary from about 0.01 microns to about 10 microns. At higher levels of addition, for example, the thickness may be from about 3 microns to about 8 microns. At lower levels of addition, however, the thickness may be from about 0.1 microns to about 1 microns, such as from about 0.3 microns to about 0.7 microns.

At relatively low levels of addition, the additional compositions can also be applied to the base sheet differently than at relatively high levels of addition. For example, at relatively low levels of addition, not only individual treated areas are formed on the main sheet, but also the additive composition may better flow over the topography of the main sheet. For example, in one embodiment, it was found that the additive composition flows along the creping pattern of the base sheet when the base sheet is creped.

The thermoplastic resin contained in the additive composition may vary depending on the particular application and the expected result. In one embodiment of the invention, for example, the thermoplastic resin is an olefin polymer. The olefin polymer used in the present invention belongs to the class of open chain unsaturated hydrocarbons having the general formula C _n H _2n . The olefin polymer may be present in the form of a copolymer, such as an interpolymer. Essentially, the olefin polymer used in the present invention refers to a polymer that contains less than about 1% substitution.

In one specific embodiment of the invention, for example, the olefin polymer may comprise an ethylene alpha-olefin interpolymer with at least one comonomer selected from the group consisting of C ₄ -C ₂₀ linear, branched or cyclic dienes, a vinyl compound such as vinyl acetate, and a compound represented by the formula H ₂ C = CHR, in which R represents a C ₁ -C ₂₀ linear, branched or cyclic alkyl group or a C ₆ -C ₂₀ aryl group. Examples of comonomers include propylene, 1-butene, 3-methyl-1-butene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-heptene, 1-hexene, 1-octene, 1-decene and 1 -dedecen. In some embodiments, the ethylene interpolymer has a density of less than about 0.92 g / cm ³ .

In other embodiments, the thermoplastic resin comprises an alpha olefin propylene interpolymer with at least one comonomer selected from the group consisting of ethylene, C ₄ -C ₂₀ linear, branched or cyclic dienes and a compound represented by the formula H ₂ C = CHR, in which R represents a C ₁ -C ₂₀ linear, branched or cyclic alkyl group or a C ₆ -C ₂₀ aryl group. Examples of comonomers include ethylene, 1-butene, 3-methyl-1-butene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-heptene, 1-hexene, 1-octene, 1-decene and 1 -dedecen. In some embodiments, the comonomer is present in an amount of from about 5 wt.% To about 25 wt.% Of the interpolymer. In one embodiment, a propylene-ethylene interpolymer is used.

Other examples of thermoplastic resins that may be used in the present invention include homopolymers and copolymers (including elastomers) of an olefin such as ethylene, propylene, 1-butene, 3-methyl-1-butene, 4-methyl-1-pentene, 3- methyl 1-pentene, 1-heptene, 1-hexene, 1-octene, 1-decene and 1-dodecene, represented, as typical examples, by polyethylene, polypropylene, poly-1-butene, poly-3-methyl-1 -butene, poly-3-methyl-1-pentene, poly-4-methyl-1-pentene, a copolymer of ethylene and propylene, a copolymer of ethylene and 1-butene and a copolymer of propylene and 1-butene; copolymers (including elastomers) of an alpha-olefin with a conjugated or unconjugated diene, represented, as typical examples, by a copolymer of ethylene and butadiene and a copolymer of ethylene and ethylidene norbornene; and polyolefins (including elastomers), such as copolymers of two or more alpha-olefins with a conjugated or unconjugated diene, represented, as typical examples, by ethylene-propylene-butadiene copolymer, ethylene-propylene-dicyclopentadiene copolymer, ethylene-propylene-1,5 -hexadiene copolymer and ethylene-propylene-ethylidene-norbornene copolymer; copolymers of vinyl compounds and ethylene, such as copolymers of vinyl acetate and ethylene with N-methylol functional comonomers, copolymers of ethylene and vinyl alcohol with N-methylol functional comonomers, a copolymer of vinyl chloride and ethylene, copolymers of ethylene and acrylic acid or ethylene and (meth) acrylic acid, and a copolymer of ethylene and (meth) acrylate; styrene copolymers (including elastomers) such as polystyrene, ABS (acrylonitrile butadiene styrene), a copolymer of acrylonitrile and styrene, a copolymer of methyl styrene and styrene; and styrene block copolymers (including elastomers), such as a styrene-butadiene copolymer and its hydrate, and styrene-isoprene-styrene three-block copolymer; polyvinyl compounds such as polyvinyl chloride, polyvinylidene chloride, vinyl chloride-vinylidene chloride copolymer, polymethyl acrylate and polymethyl methacrylate; polyamides such as nylon 6, nylon 6.6, and nylon 12; thermoplastic polyesters such as polyethylene terephthalate and polybutylene terephthalate; polycarbonate, polyphenylene oxide and the like. These resins can be used either alone or in combination of two or more resins.

In particular embodiments of the invention, polyolefins, such as polypropylene, polyethylene and copolymers thereof, and mixtures thereof, as well as ethylene-propylene-diene terpolymer are used. In some embodiments, olefin polymers include homogeneous polymers described in US Pat. No. 3,645,992 (Elston); high density polyethylene (HDPE), as described in US patent No. 4076698 (Anderson); heterogeneously branched linear low density polyethylene (LLDPE); extremely low density heterogeneously branched linear polyethylene (ULDPE); homogeneously branched linear ethylene / alpha olefin copolymers; homogeneously branched, substantially linear ethylene / alpha-olefin polymers that can be prepared, for example, by the method disclosed in US Pat. Nos. 5,272,236 and 5,278,272; the description of the method disclosed in these patents is hereby incorporated by reference; and radical polymerization and high pressure polymers and ethylene copolymers such as low density polyethylene (LDPE). In yet another embodiment of the present invention, the thermoplastic resin comprises a copolymer of carboxylic acid and ethylene, such as a copolymer of ethylene and acrylic acid (EAA) and copolymers of ethylene and methacrylic acid, such as, for example, commercially available under the trademark PRIMACOR ™ from The Dow Chemical Company, NUCREL ™ at DuPont and ESCOR ™ at ExxonMobil, and described in US Pat. Nos. 4,599,392, 4,988,781 and 5,384,373, each of which are incorporated herein by reference, and vinyl acetate / ethylene copolymers (EVA). In some embodiments, the polymer compositions described in US Pat. Nos. 6,538,070, 6,566,446, 5,869,575, 6,448,341, 5,677,383, 6,316,549, 6,111,023 or 5,844,045, all of which are incorporated herein by reference in their entirety, are also suitable. Also, of course, polymer blends can be used. In some embodiments of the invention, the blends include two different Ziegler-Natta polymers. In other embodiments, mixtures may include mixtures of Ziegler-Natta and a metallocene polymer. In still other embodiments, the thermoplastic resin used in the present invention is a mixture of two different metallocene polymers.

In one specific embodiment, the thermoplastic resin comprises an alpha olefin ethylene interpolymer with an alkene-containing comonomer, such as 1-octene. A copolymer of ethylene and octene may be present in the additive composition alone or in combination with another thermoplastic resin, such as a copolymer of ethylene and acrylic acid. The advantage is that the copolymer of ethylene and acrylic acid is not only a thermoplastic resin, but also serves as a dispersant. For some embodiments of the invention, it is necessary that the additive composition contains a film-forming composition. It was found that a copolymer of ethylene and acrylic acid promotes film formation, while a copolymer of ethylene and octene reduces stiffness. When applied to a tissue sheet, the composition may or may not form a film on the inside of the product, depending on how the composition is applied and the amount of composition that is applied. When a film is formed on a tissue web, the film may be continuous or intermittent. When co-present, the weight ratio between the ethylene-octene copolymer and the ethylene-acrylic acid copolymer can range from about 1:10 to about 10: 1, such as from about 3: 2 to about 2: 3.

A thermoplastic resin, such as a copolymer of ethylene and octene, may have a crystallinity of less than about 50%, such as less than about 25%. The polymer can be obtained by using a single site catalyst and can have a weight average molecular weight of from about 15,000 to about 5 million, such as from about 20,000 to about 1 million. The molecular weight distribution of the polymer may range from about 1.01 to about 40, such as from about 1.5 to about 20, or, for example, from about 1.8 to about 10.

Depending on the thermoplastic polymer, the polymer melting index can range from about 0.001 g / 10 min to about 1,000 g / 10 min, such as from about 0.5 g / 10 min to about 800 g / 10 min. For example, in one embodiment of the invention, the melting index of the thermoplastic resin may range from about 100 g / 10 min to about 700 g / 10 min.

The thermoplastic resin may also have a relatively low melting point. For example, the melting point of the thermoplastic resin may be lower than about 140 ° C, such as lower than 130 ° C or, for example, lower than 120 ° C. For example, in one embodiment of the invention, the melting point is lower than about 90 ° C. The glass transition temperature of the thermoplastic resin may also be relatively low. For example, the glass transition temperature may be lower than about 50 ° C, such as lower than about 40 ° C.

The additive composition may contain one or more thermoplastic resins in an amount of from about 1 wt.% To about 96 wt.%. For example, a thermoplastic resin may be present in the aqueous dispersion in an amount of from about 10 wt.% To about 70 wt.%, Such as from about 20 wt.% To about 50 wt.%.

In addition to at least one thermoplastic resin, the aqueous dispersion may also contain a dispersant. A dispersing agent is one that promotes the formation and / or stabilization of a dispersion. One or more dispersing agents may be included in the additive composition.

In general, any suitable dispersing agent may be used. In one embodiment of the invention, for example, the dispersing agent comprises at least one carboxylic acid, a salt of at least one carboxylic acid or a carboxylic acid ester or a carboxylic acid ester salt. Examples of carboxylic acids suitable as a dispersant include fatty acids such as montanic acid, stearic acid, oleic acid and the like. In some embodiments of the invention, a carboxylic acid, a carboxylic acid salt, or at least one carboxylic acid carboxylic acid moiety, or at least one carboxylic acid moiety in a carboxylic acid ester salt has less than 25 carbon atoms . In other embodiments, a carboxylic acid, a carboxylic acid salt, or at least one carboxylic acid ester moiety or at least one carboxylic acid moiety in a carboxylic ester salt has 12 to 25 atoms carbon. In some embodiments of the invention, carboxylic acids, carboxylic acid salts, at least one carboxylic acid carboxylic acid ester or a salt thereof having from 15 to 25 carbon atoms are preferred. In other embodiments, the number of carbon atoms is from about 25 to 60. Some examples of salts comprise a cation selected from the group consisting of an alkali metal cation, an alkaline earth metal cation, or an ammonium or alkylammonium cation.

In still other embodiments, the dispersant is selected from the group consisting of ethylene carboxylic acid polymers and their salts, such as ethylene-acrylic acid copolymers or ethylene-methacryloric acid copolymers.

In other embodiments, the dispersing agent is selected from alkyl ether carboxylates, oil sulfonates, sulfonated polyoxyethylene alcohol, sulfated or phosphated polyoxyethylene alcohols, polyethylene ethylene oxide / propylene oxide / ethylene oxide dispersants, primary and secondary alcohol ethoxylates, alkyl glycosides and

When using a copolymer of ethylene and acrylic acid as a dispersant, the copolymer can also serve as a thermoplastic resin.

In one specific embodiment, the aqueous dispersion comprises a copolymer of ethylene and octene, a copolymer of ethylene and acrylic acid and a fatty acid such as stearic acid or oleic acid. A dispersant, such as a carboxylic acid, may be present in the aqueous dispersion in an amount of from about 0.1 wt.% To about 10 wt.%.

In addition to the above components, the aqueous dispersion also contains water. Water can be added as tap water, and as deionized water. The pH of the aqueous dispersion is generally less than about 12, such as from about 5 to about 11.5, such as from about 7 to about 11. The aqueous dispersion may have a solids content of less than about 75%, such as less than about 70%. For example, the solids content of the aqueous dispersion may range from about 5% to about 60%. In general, the solids content may vary depending on the manner in which the additive composition is applied to or included in the tissue web. For example, when incorporated into a tissue web during formation, such as when added with an aqueous suspension of fibers, a relatively high solids content can be used. In surface applications such as spraying or printing, however, a lower solids content can be used to improve the performance of the spray or printing device.

Although any method can be used to produce an aqueous dispersion, in one embodiment, the dispersion can be formed through a melting and mixing process. For example, a kneading device may comprise a Banbury mixer, single screw extruder or multi-screw extruder. Mixing melting can be carried out under conditions that are commonly used for melting and mixing one or more thermoplastic polymers.

In one particular embodiment, the process includes melting and mixing the components that make up the dispersion. The mixing melting device may include a plurality of inlets for various components. For example, an extruder may include four inlets for various components. For example, an extruder may include four inlets arranged in series. In addition, if desired, a vacuum tank may be added to the possible position of the extruder.

In some embodiments, the dispersion is first diluted to a content of from about 1 to about 3 wt.% Water, and then subsequently diluted to a content of higher than about 25 wt.% Water.

When treating tissue webs in accordance with the present description, the additive composition containing the aqueous polymer dispersion may be applied to the tissue web superficially or may be incorporated into the tissue web by pre-mixing with the fibers used to form the web. When applied superficially, the additive composition may be applied to the tissue web in a dry or wet state. In one embodiment, the additive composition may be applied superficially to the web during the creping process. For example, in one embodiment, the additive composition may be sprayed onto a web or a heated tumble dryer to adhere the web to the drum of the dryer. The canvas can then be creped from the dryer drum. When the additive composition is applied to the web and then adhesively attached to the dryer drum, the composition may be uniformly applied to the surface area of the web or may be applied in accordance with a particular pattern.

When applied to a tissue web on a surface, the additive composition can be sprayed onto the web, extruded onto the web or printed onto the web. When extruding onto a web, any suitable extrusion device can be used, such as a crevice extruder or a melt blown extruder. When printing onto the web, any suitable printing device may be used. For example, you can use an inkjet printer or a rotogravure printing device.

In one embodiment, the additive composition may be heated prior to application to the tissue web or during application. Heating the composition may reduce viscosity to facilitate application. For example, the additive composition may be heated to a temperature of from about 50 ° C to about 150 ° C.

Tissue products made in accordance with the present description may include single-layer tissue products or multilayer tissue products. For example, in one embodiment, the product may include two layers or three layers.

In general, any suitable tissue paper may be processed as described herein. For example, in one embodiment, the base sheet may be a tissue sheet, such as toilet paper, a facial tissue, a paper towel, an industrial tissue, and the like. Napkin products have a volume of at least 3 cc / g. Napkin products may contain one or more layers and may be made of any suitable types of fibers.

Fibers suitable for making tissue sheets contain any natural or synthetic fibers, including non-wood fibers such as cotton, abacus, kenaf, sabai grass, linen, esparto grass, straw, jute rope, cake, milkweed fibers and pineapple leaf fibers, but not limited to them; and wood fibers or pulp fibers, such as those obtained from deciduous and coniferous trees, including softwood fibers, such as northern and southern softwood kraft fibers; Hardwood fibers such as eucalyptus, maple, birch and aspen. Pulp fibers can be made with a high yield or with a low level of products and can be converted into pulp by any known method, including kraft, sulphate pulping, high yielding pulping methods and other known pulp production methods. You can also use fibers made using organosol methods for the manufacture of pulp, including fibers and methods described in US patent No. 4793898, issued December 27, 1988, Laamanen and others; US patent No. 4594130, issued June 10, 1986, Chang and others; and in US patent No. 3585104. The fibers used can also be produced using anthraquinone pulp, given as an example in US patent No. 5595628, issued January 21, 1997, Gordon and others.

Part of the fibers, such as up to 50% dry weight or lower, or from about 5% to about 30% dry weight, can be synthetic fibers such as rayon, polyolefin fibers, polyester fibers, sheath-core bicomponent fibers, multicomponent binder fibers and etc. An exemplary polyethylene fiber is Fybrel® available from Minifibers, Inc (Jackson City, TN). You can use any known method of whitening. Cellulose-type artificial fibers include viscose in all its varieties and other fibers derived from viscose or chemically modified cellulose. Chemically treated natural cellulosic fibers such as mercerized pulp, chemically strengthened fibers or cross-linked fibers, or sulfonated fibers can be used. For good mechanical properties when using paper fibers, it is preferred that the fibers are relatively intact and almost unpeeled or only slightly peeled. Although recyclable fibers can be used, primary fibers are generally more suitable for their mechanical properties and the absence of contamination. Mercerized fibers, regenerated cellulosic fibers, cellulose produced by microorganisms, rayon and other cellulosic material or cellulose derivatives can be used. Suitable papermaking fibers may include recycled fibers, primary fibers, or mixtures thereof. In particular embodiments, fibers capable of high bulk and good compression properties can have a Canadian Grind Standard of at least 200, more specifically at least 300, even more specifically at least 400, even more specifically at least 500.

Other papermaking fibers that can be used in the present invention include paper waste or recycled fibers and high yield fibers. High yield pulp fibers are papermaking fibers produced by a pulp production process that provides a productivity of about 65% or more, more specifically about 75% or more, even more specifically, from about 75% to about 95%. Productivity is the resulting amount of processed fibers, expressed as a percentage of the original wood pulp. Such pulp production processes include bleached chemothermomechanical pulp (VSTMP), chemothermomechanical pulp (TMP), thermomechanical chemical pulp (TMP), high yield sulphite pulp and high yield kraft pulp, all of which provide the resulting fibers with a high level of lignin . High yield fibers are well known for their stiffness in both dry and wet conditions relative to conventional chemically pulped fibers.

In general, any process capable of forming a base sheet may also be used in the present description. For example, the papermaking process of the present invention may use creping, wet creping, double creping, corrugating, wet pressing, air pressing, drying through a stream of air, drying through a stream of air with a crepe, drying through a stream of air without creping, hydraulic weaving, air laying, co-molding processes, and other steps known in the art.

Also suitable for the products of the present invention are tissue sheets that have a sealing pattern or a printed pattern, such as tissue sheets described in any of the following US Patent Nos. 4,514,345, issued April 30, 1985, Johnson et al .; 4,528,239, issued July 9, 1985, Trokhan; 5098522, issued March 24, 1992., 5260171, issued November 9, 1993, Smurkoski et al .; 5,275,700, issued January 4, 1994, Trokhan; 5328565, issued July 12, 1994, Rasch et al .; 5,334,289 issued August 2, 1994 to Trokhan et al .; 5431786, issued July 11, 1995, Rasch et al .; 5496624 issued March 5, 1996, Steltjes, Jr. and etc.; 5500277, issued March 19, 1996, Trokhan et al .; 5514523, issued May 7, 1996, to Trokhan et al .; 5554467, issued September 10, 1996, Trokhan et al .; 5566724, issued October 22, 1996, Trokhan et al .; 5624790, issued April 29, 1997, Trokhan et al .; and 5628876, issued May 13, 1997, Ayers et al., the disclosures of which are incorporated herein by reference to the extent that they do not contradict those described herein. Such printed tissue sheets may have a grid of sealed areas that are printed on the dryer of the drying apparatus by printing material, and areas that are relatively less densified (eg, “domed protrusions” in the tissue sheet) corresponding to deflecting channels in the printed material, while the tissue sheet located above the deflecting channels was deflected by the difference in air pressure through the deflecting channel with the formation of areas such as pillows, low lotnosti projections or dome in the tissue sheet.

A tissue web can also be formed without a significant amount of fiber-to-fiber bond strength. In this regard, the fiber composition used to form the base web can be treated with a bond breaking chemical. The bond breaker can be added to the fiber slurry during the pulping process or can be sent directly to the headbox. Suitable bond disruption agents that can be used in the present invention include cationic bond disruptors such as aliphatic dialkyl quaternary amine salts, aliphatic monoalkyl salts of tertiary amine salts, primary amine salts, imidazoline quaternary salts, imidazoline quaternary salts and unsaturated aliphatic alkyl salts amine. Other suitable coupling disruption agents are disclosed in US Pat. No. 5,529,665 (Kaun), which is incorporated herein by reference. In particular, Kaun discloses the use of cationic silicon compositions as a bond disrupter.

In one embodiment of the invention, the bond breaking agent used in the method of the present invention is an organic quaternary ammonium chloride and, in particular, a silicon-based amine salt of a quaternary ammonium chloride. For example, a bond cleaving agent may be a PROSOFT® TQ1003 product distributed by the Hercules Corporation. A bond breaker may be added to the fiber suspension in an amount of about 1 kg per metric ton to about 10 kg per metric ton of fibers present within the fiber suspension.

In an alternative embodiment, the bond cleaving agent may be an imidazoline-based agent. Imidazoline-based bond disruption agent can be purchased, for example, from Witco Corporation. Imidazoline-based bond breaker may be added in an amount of 2.0 to about 15 kg per metric ton.

In one embodiment, the release agent can be added to the fiber composition in accordance with the process described in PCT application having international publication WO 99/34057, filed December 17, 1998, or in published PCT application having international publication WO 00/66835 April 28, 2000, both of which are incorporated herein by reference. The above publications describe a process in which a chemical additive, such as a release agent, is highly absorbed into the cellulose paper fibers. This process includes the steps of treating the fiber suspension with excess chemical additives, providing sufficient residence time for adsorption to occur, filtering the suspension to remove non-adsorbed chemical additives, and redispersing the filtered pulp with fresh water before forming the non-woven fabric.

Possible chemical additives can also be added to the aqueous fiber composition or to the formed starting web to give additional benefits to the product and process, but not inconsistent with the advantages achieved in the present invention. The following materials are included as examples of additional chemicals that can be applied to the web using the additive composition of the present invention. Chemicals are included as examples and are not intended to limit the scope of the present invention. Such chemicals can be added at any point in the paper manufacturing process, including adding simultaneously with the additive composition during the pulp production process, wherein said additive or additives are mixed directly with the additive composition.

Additional types of chemicals that can be added to the paper web include excipients, usually in the form of cationic, anionic or nonionic surfactants, wetting agents and plasticizers, such as low molecular weight polyethylene glycol, polyhydroxy compounds such as glycerol and propylene glycol, but not limited to. Materials that provide skin health benefits such as mineral oil, aloe extract, vitamin E, silicones, lotions, in general, can be incorporated into finished products.

In general, the products of the present invention can be used in conjunction with any known materials and chemicals that do not contradict the intended use. Examples of such materials include odor control agents such as odor absorbent materials, activated carbon fibers and particles, baby powder, baking soda, chelating agents, zeolite, perfumes or other odor masking agents, cyclodextrin compounds, oxidizing agents, and the like, but not limited to them. Additional substances include cationic dyes, optical brighteners, moisturizers, emollients, and the like.

The various chemicals and ingredients that may be included on the base sheet may depend on the end use of the product. For example, various wet strength agents may be included in the product. For products such as toilet paper, for example, substances that impart temporary wet strength can be used. As used here, substances that impart temporary strength in the wet state are materials used to fix the joints between the fibers in the wet state. Typically, the means by which the fibers are held together in paper and tissue products include hydrogen bonds and sometimes combinations of hydrogen bonds and covalent and / or ionic bonds. In some applications, it may be preferable to provide a material that will allow bonding with the fibers, so as to fix the fiber-to-fiber bonding points and make them resistant to wet degradation. A wet state usually means that the product is highly saturated with water or other aqueous solutions.

Any material that, when added to paper or tissue paper, results in a sheet with a ratio of geometric average tensile strength in the wet state: tensile strength in the dry state is more than 0.1, can be called a substance that gives strength in the wet state.

Substances that impart temporary wet strength, which are usually included in toilet paper, are formed as those polymers which, when incorporated into paper or tissue products, provide a product that holds less than 50% of its original wet strength after exposure to water for at least 5 minutes. Substances that give temporary strength in the wet state include polymeric compounds of the aldehyde functional group, such as glyoxylated polyacrylamide, such as cationic glyoxylated polyacrylamide.

Such compounds include PAREZ 631 NC wet strength polymer, available from Cytec Industries, West Patterson, N.J., chloroxylate polyacrylamides and HERCOBOND 1366 manufactured by Hercules, Inc., Wilmington, Del. Another example of glyoxylate polyacrylamide is PAREZ 745, which is a glyoxylated copolymer of acrylamide and diallyldimethylammonium chloride.

For toilet paper and other tissue products, on the other hand, substances that impart a constant wet strength can be included in the base sheet. Substances that impart constant wet strength are also well known in the art and provide a product that will retain more than 50% of the original wet strength after exposure to water for a period of at least 5 minutes.

Already formed products can be packaged in various ways. For example, in one embodiment, a sheet type product may be cut into individual sheets stacked before being placed in a package. Alternatively, a sheet type product may be wound spirally. By spiral winding together, each individual sheet can be separated from the adjacent sheet by a weakened line, such as a perforation line. Toilet paper and paper towels, for example, are usually delivered to the consumer in a spirally wound configuration.

Tissue webs that can be processed in accordance with the present invention may include a single homogeneous layer of fibers or may include a multilayer or layered structure. For example, a tissue web layer may include two or more layers of fibers. Each layer may have different fiber compositions. For example, referring to FIG. 1, one embodiment of a device for forming a multilayer pulp composition is shown. As shown, the three-layer headbox 10 generally includes an upper wall 12 of the headbox and a lower wall 14 of the headbox. The headbox 10 further includes a first spacer 16 and a second spacer 18, which separate the three layers of the fiber composition.

Each of the fibrous layers contains a dilute aqueous suspension of paper fibers. The particular fibers contained in each layer generally depend on the product to be formed and on the preferred results. For example, the composition of the fibers of each layer may vary depending on whether toilet paper, face wipes or paper towels should be obtained. In one embodiment, for example, the middle layer 20 contains only kraft soft southern wood fibers or in combination with other fibers, such as high yield fibers. The outer layers 22 and 24, on the other hand, contain softwood fibers, such as soft northern wood kraft fibers.

In an alternative embodiment, the middle layer may comprise softwood fibers for strength, while the outer layers may comprise hardwood fibers such as eucalyptus fibers to give a soft feel.

The endless moving forming material 26, suitably supported and driven by rolls 28 and 30, receives layered paper pulp discharged from headbox 10. While holding layered fiber suspension on material 26, water is passed through the material as shown by arrows 32. Removal water is achieved through a combination of gravity, centrifugal force and vacuum suction depending on the molding configuration.

The formation of multilayer paper webs is also described and disclosed in US Patent No. 5129988, Farrington Jr., which is incorporated herein by reference.

In accordance with the present description, the additive composition, in one embodiment, can be combined with an aqueous suspension of fibers that are fed into the headbox 10. The additive composition, for example, can be applied to only one layer in a layered fiber composition or to all layers. When added in the wet part of the process or otherwise combined with an aqueous suspension of fibers, the additive composition becomes incorporated into the entire fibrous layer.

When combined in a wet portion with an aqueous suspension of fibers, a retention aid may be present in the additive composition. For example, in one particular embodiment, the retention aid may comprise polydiallyldimethylammonium chloride or any suitable cationic substance. The additive composition may be included in the tissue web in an amount of from about 0.01 wt.% To about 30 wt.%, Such as from about 0.5 to about 20 wt.%. For example, in one embodiment, the additive composition may be present in an amount of up to 10 wt.%. The percentages indicated above are based on the solids content that is added to the tissue.

The weight of the basis of tissue paper, made in accordance with the present description, may vary depending on the final product. For example, this process can be used to produce toilet paper, face wipes, paper towels, industrial wipes, and the like. In general, the basis weight of tissue products can vary from 10 g / m2 to about 110 g / m2, such as from about 20 g / cm 2 to about 90 g / cm 2. For toilet paper and facial wipes, for example, the weight of the base can vary in the range from about 10 g / m2 to about 40 g / m2. For paper towels, on the other hand, the weight of the base can vary from about 25 g / m2 to about 80 g / m2.

The volume of the tissue web may also vary from about 3 cc / g to 20 cc / g, such as from about 5 cc / g to about 15 cc / g. The "bulk" of the sheet is calculated as the quotient of the thickness (caliber) of the dry tissue sheet, expressed in microns, divided by the dry weight of the base, expressed in grams per square meter. The resulting sheet volume is expressed in cubic centimeters per gram. More specifically, the caliber is measured as the total thickness of a stack of ten sheets and divide the total thickness of the stack by ten, with each sheet in the stack located on the same side up. The gauge is measured in accordance with the test method TAPPI om-89 "Thickness (caliper) of Paper, Paperboard and Combined Board" with note 3 for stacked sheets. The micrometer used to implement the T411 om-89 is an Emveco 200-A napkin caliper tester, from Emveco, Inc., Newberg, Oregon. The micrometer has a load of 2.00 kPa (132 grams per square inch), the area of the pressure section is 2500 square millimeters, the diameter of the pressure section is 56, 42 millimeters, the residence time is 3 seconds and the drop rate is 0.8 millimeters per second.

In multilayer products, the basis weight of each tissue web present in the product may also vary. In general, the total weight of the base of the multilayer product will be the same as described above, such as from about 20 g / m2 to about 110 g / m2. Thus, the basis weight of each layer can be from about 10 g / m2 to about 60 g / m2, such as from about 20 g / m2 to about 40 g / m2.

Once an aqueous suspension of fibers is formed into a tissue web, the tissue web can be processed using various technologies and methods. For example, referring to FIG. 2, a method for making a through-flow dried tissue sheet is shown. (For simplicity, the various idler rolls schematically used to determine the movement of various materials are shown but not numbered. It will be understood that changes can be made in the apparatus and method shown in FIG. 2 without departing from the general process). Shown is a two-mesh forming device having a paper headbox 34, such as a multilayer headbox, which injects and places a stream 36 of an aqueous suspension of paper fibers on a molding material 38 located on the forming roll 39. The molding material serves to maintain and transfer the newly formed wet material down downstream in the process when the web is partially dehydrated to a consistency of about 10 percent dry weight. Additional dewatering of the wet web can be effected, for example, by vacuum absorption, while the wet web is supported by the molding material.

The wet web is then moved from the molding material to the transfer material 40. In one embodiment, the transfer material can move at a lower speed than the molding material to give the fabric increased strength. This is commonly called a “swift” transfer. Preferably, the transfer material may have a void volume that is equal to or less than the void volume of the molding material. The relative difference in speeds between the two materials can be from 0 to 60%, more specifically from about 15 to 45%. The transfer is preferably carried out using a vacuum guide 42, so that the molding material and the transfer material simultaneously converge and diverge at the leading edge of the vacuum hole.

The web is then moved from the transfer material to the through drying material 44 using a vacuum transfer roll 46 or a vacuum transfer guide, possibly again using a fixed non-contact transfer, as described above. The drying material in the through flow can move at approximately the same speed or at a different speed relative to the transfer material. If desired, the material for drying in the air stream can move at a lower speed to further increase the elongation. The transfer can be carried out using vacuum to ensure the deformation of the sheet to match the material for through drying, while providing the desired bulk and appearance if desired. Suitable materials for through drying are described in US Pat. No. 5,429,686 to Kai F. Chiu et al. And US Pat. No. 5,672,248 to Wendt et al., Which are incorporated herein by reference.

In one embodiment, the through-drying material comprises tall and long extruded prints. For example, through-drying material may have from about 5 to about 300 extruded impressions per square inch that protrude at least about 0.005 inches above the plane of the material. During the drying process, the web can be macroscopically positioned to match the surface of the material for through drying and to form a three-dimensional surface. Flat surfaces, however, can also be used in the present invention.

The side of the web in contact with the material for through drying is commonly referred to as the “material side” of the paper web. The material side of the paper web, as described above, may have a shape that corresponds to the surface of the through drying material after the material is dried in the through drying device. The opposite side of the paper web, on the other hand, is usually called the "air side". The air side of the web is usually smoother than the side of the material during normal through drying processes.

The vacuum level used to transfer the web can range from about 3 to about 15 inches of mercury (75 to about 380 millimeters of mercury), preferably about 5 inches (125 millimeters) of mercury. The vacuum guide (negative pressure) can be supplemented or replaced by using positive pressure from the opposite side of the web to blow the web to the next material in addition to or as a substitute for suctioning it to the next web by vacuum. Also, a vacuum roll or rolls can be used to replace the vacuum guide (s).

The web supported by the through-drying material is finally dried to a consistency of about 94% or higher using the through-drying device 48, and then transferred to the transfer material 50. The dried base sheet 52 is transferred to the bobbin 54 using the transfer material 50 and possible transfer material 56. Possible pressure swivel roller 58 can be used to facilitate transfer of the web from transfer material 50 to material 56. Suitable transfer materials for this purpose are Albany International 84M or 94 and Asten 959 or 937, all of which are relatively smooth materials having a fine pattern. Although not shown, roll calendaring or subsequent off-process calendering can be used to improve the smoothness and softness of the base sheet.

In one embodiment, the roll 54 shown in FIG. 2 can move at a speed less than the material 56 during the “rapid” transfer process to form the creping elements in the paper web 52. For example, the relative speed difference between the roll and the material can be from about 5% to about 25%, and more specifically, from about 12% to about 14%. Rapid transfer on a roll can occur either alone or in conjunction with the rapid transfer process upstream, such as between a molding material and a transfer material.

In one embodiment, paper web 52 is a textured web that has been dried in a three-dimensional state, so that hydrogen bonds connecting the fibers are essentially formed, although the web was not in a planar, planar state. For example, a web may be formed when the web is on a highly textured through-drying material or other three-dimensional substrate. Processes for the production of uncreated materials for through-flow drying, for example, are described in US Pat. No. 5,672,248, Wendt et al., US Pat. No. 5,656,132, Farrington et al., US Pat. No. 6,120,642, Lindsay and Burazin, US Pat. No. 6,096,169. Hermans and others, US patent No. 6197154, Chen and others and US patent No. 6143135, Hada and others, all of which are fully incorporated herein by reference.

As described above, the additive composition may be combined with an aqueous suspension of fibers used to form the tissue web 52. Alternatively, the additive composition may be locally applied to the tissue web after it has been formed. For example, as shown in FIG. 2, the additive composition may be applied to the tissue web before the drying device 48 or after the drying device 48, for example, by using a spray device 49A or a spray device 49B, respectively.

Figure 2 shows the process for the production of uncreated dried in a continuous air stream tissue towels. It should be understood, however, that the additive composition can be applied to tissue webs in other processes for making wipes. For example, referring to FIG. 3, one embodiment of a process for forming creped wet-pressed tissue sheets is shown. In this embodiment, the headbox 60 releases an aqueous suspension of fibers onto the molding material 62, which is supported and driven by a plurality of guide rolls 64. A vacuum box 66 is located under the molding material 62 and is adapted to remove water from the fiber composition to facilitate web formation. From the molding material 62, the formed web 68 moves to the second material 70, which can be either wire or felt. Material 70 is supported to travel along a continuous path using a plurality of guide rolls 72. A lifting roll 74 is also included to facilitate transfer of web 68 from material 62 to material 70.

From material 70, web 68 in this embodiment is transferred to the surface of a rotatable heated dryer drum 76, such as a Yankee dryer.

In accordance with the present invention, the additive composition may be included in the tissue web 68 by combining with the aqueous suspension of the fibers contained in headbox 60 and / or by local application of the additive composition during the process. In one particular embodiment, the additive composition of the present invention can be applied locally to the tissue web 68, the web being transported on the material 70, or it can be applied to the surface of the dryer drum 76 to transfer onto one side of the tissue web 68. Thus, the additive composition is used for adhering the tissue web 68 to the dryer drum 76. In this embodiment, when the web 68 is transferred through a portion of the path of rotation of the drum surface to the web Well apply heat, causing the evaporation of most of the moisture contained in the canvas. The web 68 is then removed from the drying drum 76 by means of a creping knife 78. The creping of the web 78, when formed, reduces internal connection within the web and increases softness. Applying the additive composition to the web during the creping process, on the other hand, can increase the strength of the web.

Referring to FIG. 35, another alternative embodiment of a process for forming creped tissue towels is shown. Similar reference numerals were used to indicate similar elements with respect to the process shown in FIG. 3.

As shown in FIG. 35, the formed web 68 is transferred onto the surface of a rotatable heated dryer drum 76, which may be a Yankee drum. The pinch roller 72 may, in one embodiment, comprise a suction side roller. In order to adhesively attach the web 68 to the surface of the dryer drum 76, a creping adhesive can be applied to the surface of the dryer drum using a spray device 69. The spray device 69 can release an additive composition made in accordance with the present description, or can release a traditional creping adhesive.

As shown in FIG. 35, the web is adhesively attached to the surface of the drying drum 76, and then creped from the drum using a creping knife 78. If desired, the drying drum 76 may be connected to the housing 71. The housing 71 may be used to pump air from or through the web 68.

The web 68 creped from the dryer drum 76 is then adhesively attached to the second dryer drum 73. The second dryer drum 73 may comprise, for example, a heated drum surrounded by a casing 77. The drum may be heated to a temperature of from about 250 ° C. to about 200 ° C. for example, from about 100 ° C to about 150 ° C.

In order to adhesively attach the web 68 to the second drying drum 73, the second spraying device 73 may release adhesive onto the surface of the drying drum. According to the present invention, for example, the second spray device 75 may release the additive composition as described above. The additive composition not only promotes the adhesive attachment of the tissue web 68 to the dryer drum 73, but also transfers to the surface of the canvas when the fabric is creped from the dryer drum 73 using a creping knife 79.

Already creped from the second drying drum 73, the web 68 may possibly be fed around the knurling drum 81 and cooled before being wound onto a roll 83.

The additive composition can also be used in subsequent molding processes. For example, in one embodiment, the additive composition may be used in the creping process with printing and applied to a preformed web. More specifically, it has been found that the additive composition already locally applied to the tissue web is well suited for adhering the tissue web adherently to a creping surface, such as during a creping operation with printing.

For example, when a tissue web is formed and dried, in one embodiment, the additive composition can be applied to at least one side of the web, and then at least one side of the web can be creped. In general, the additive composition can only be applied to one side of the fabric and only one side of the fabric can be creped, the additive composition can be applied to both sides of the fabric or the additive composition can be applied to each side of the fabric and each side the canvas can be creped.

Referring to FIG. 4, one embodiment of a system is shown that can be used to apply an additive composition to a tissue web and to crep one side of the web. The embodiment shown in FIG. 4 may be an in-line process or an off-stream operation. As shown, the tissue web 80, made in accordance with the process shown in FIG. 2 or FIG. 3 or in accordance with a similar process, passes through the first work station for applying the additive composition, generally indicated at 82. Work station 82 includes a clamp formed by a smooth rubber clamping roller 84 and a patterned rotogravure roller 86. The rotogravure roller 86 is connected to the reservoir 88 containing the first additive composition 90. The rotogravure roller 86 applies the additive composition 90 on one side olotna 80 in the form of a preselected pattern.

The web 80 is then contacted with the heated roller 92 after passing the roller 94. The heated roller 92 can be heated to a temperature of, for example, about 200 ° C, and more specifically, about 100 ° C to about 150 ° C. In general, the web may be heated to a temperature sufficient to dry the web and evaporate any water.

It should be understood. That in addition to the heated roller 92 for drying the canvas can be used with any heating device. For example, in an alternative embodiment, the web may be placed in communication with an infrared heating device to dry the web. In addition to using a heated roll or infrared heating device, other heating devices, such as any suitable convection oven or microwave oven, can be included.

From the heated roller 92, the web 80 can be advanced by the pushing rollers 96 to a second workstation for applying the additive composition, generally indicated at 98. Workstation 98 includes a transfer roll 100 in contact with the rotogravure roller 102, which is in communication with the reservoir 104 containing the second additive composition 106. Similar to the workplace 82, the second additive composition 106 is applied to the opposite side of the web 80 in the form of a pre-selected pattern. As soon as the second additive composition is applied, the web 80 is adhesively attached to the creping roll 108 using a pinch roll 110. The blade 80 is transferred to the surface of the creping drum 108 at a distance, and then removed from it by the operation of the creping knife 112. The creping knife 112 produces a controlled the operation of the creping pattern on the second side of the tissue.

In this embodiment, the already creped tissue towel 80 is pushed through the drying station 114. Drying station 114 may include any form of heating unit, such as an oven, driven by infrared heat, microwave energy, hot air, or the like. A drying station 114 may be necessary in some applications for drying the web and / or curing the additive composition. Depending on the selected additive composition, however, in other applications, a drying station 114 may not be necessary.

The degree of heating of the tissue web in the drying workstation 114 may depend on the particular thermoplastic polymer used in the additive composition, the amount of composition deposited on the web, and the type of web used. In some applications, for example, a tissue web can be heated using a gas stream, such as air, at a temperature of from about 100 ° C to about 200 ° C.

In one embodiment, shown in FIG. 4, although the additive composition is applied to each side of the tissue web, only one side of the cloth is subjected to a creping process. It should be understood, however, that in other embodiments, both sides of the web may be creped. For example, the heated roller 92 may be replaced by a creping drum, such as the drum 108 shown in FIG. 4.

The creping of a tissue web, as shown in FIG. 4, increases the softness of the web by breaking the fiber-to-fiber compounds contained in the tissue web. Applying the additive composition to the outside of the paper web, on the other hand, not only promotes creping of the web, but also adds dry strength, wet strength, tensile and tensile strength to the web. In addition, the additive composition reduces the release of fluff from the tissue web.

In general, the first additive composition and the second additive composition applied to the tissue web as shown in FIG. 4 may contain the same ingredients or may contain different ingredients. Alternatively, the additive compositions may contain the same ingredients in different amounts, if preferred.

The additive composition is applied to the main fabric, as described above, in the form of a pre-selected pattern. In one embodiment, for example, the additive composition may be applied to the web in the form of a mesh pattern, so that the pattern interconnects to form a mesh-like structure on the surface.

In an alternative embodiment, however, the additive composition is applied to the web in the form of a pattern, which is a sequence of individual forms. Application of the additive composition in the form of individual forms, such as dots, provides sufficient strength to the web without coating a significant portion of the surface area of the web.

In accordance with the present invention, the additive composition is applied to each side of the paper web so as to cover from about 15% to about 75% of the surface of the web. More specifically, in most applications, the additive composition will cover from about 20% to about 60% of the surface area of each side of the web. The total amount of additive composition applied to each side of the web can be in the range of from about 1 wt.% To about 30 wt.% Based on the total weight of the web, such as from about 1 wt.% To about 20 wt.%, As for example, from about 2 wt.% to about 10 wt.%.

In the above amounts, the additive composition may penetrate the tissue web after application in an amount up to about 30% of the total web thickness, depending on various factors. It has been found, however, that most of the additive composition is mainly located on the surface of the web after application to the web. For example, in some embodiments, the additive composition penetrates the web by less than 5%, such as less than 3%, such as less than 1% of the web thickness.

Referring to FIG. 5, one embodiment of a pattern is shown that can be used to apply an additive composition to a paper web in accordance with the present invention. As shown, the pattern shown in FIG. 5 is a sequence of individual dots 120. In one embodiment, for example, dots can be spaced so that they are present from about 25 to about 35 dpi in the machine direction or transverse machine direction direction. The dots may have a diameter of, for example, from about 0.01 inches to about 0.03 inches. In one particular embodiment, the dots may have a diameter of about 0.02 inches and may be present in the pattern such that approximately 28 dots per inch extend either in the machine direction or in the transverse machine direction. In this embodiment, the dots can cover from about 20% to about 30% of the surface area of one side of the paper web and, more specifically, can cover about 25% of the surface surface of the web.

In addition to points, various other individual forms can be used. For example, as can be seen in Fig. 7, a pattern is shown made of separate shapes, each of which consists of three elongated hexagons. In one embodiment, the hexagons may have a length of about 0.02 inches and a width of about 0.006 inches. About 35 to 40 hexagons per inch can be spaced apart in the machine direction and in the transverse machine direction. When using hexagons, as shown in FIG. 7, the pattern can cover about 40% to about 60% of the surface area of one side of the fabric, and more specifically, can cover about 50% of the surface area of the fabric.

Referring to FIG. 6, another embodiment of a pattern for applying an additive composition to a paper web is shown. In this embodiment, the pattern is a mesh structure. More specifically, the mesh structure is in the form of a diamond. When used, the mesh pattern can provide more strength to the canvas compared to patterns that are made in the form of a sequence of individual shapes.

The process that is used to apply the additive composition to a tissue web in accordance with the present invention may vary. For example, various printing methods can be used to apply the additive composition by printing onto a base sheet, depending on the particular application. Such printing methods may include direct engraving using two separate prints on each side, offset printing using two-sided printing (printing is applied on both sides at the same time), or printing from station to station (sequential printing on each side in one pass). In another embodiment, a combination of offset printing and direct gravure printing can be used. In yet another embodiment, flexographic printing can be used using either duplex printing or print from place to place for applying an additional composition.

In accordance with the process of the present invention, numerous and various products can be formed. For example, fabric products may be single layer tissue products. Products, for example, may be facial wipes, toilet paper, paper towels, sanitary napkins and industrial wipes, and the like. As indicated above, the main weight can vary anywhere from about 10 g / m2 to about 110 g / m2.

Tissue products in accordance with the above processes can have relatively good bulk properties. For example, tissue webs may have a volume above about 8 cc / g, such as above about 10 cc / g, such as above about 11 cc / g.

In one embodiment, tissue webs made in accordance with the present invention may be included in multilayer products. For example, in one embodiment, a tissue sheet made in accordance with the present invention may be attached to one or more other tissue sheets to form an absorbent product having the desired properties. Other webs laminated to the tissue web of the present invention can be, for example, wet creped webs, calendered webs, air-dried webs, creped air-dried webs, uncreated air-dried webs, hydraulically entangled webs, co-formed webs, webs laid in the air stream, and the like.

In one embodiment, when incorporating a tissue web made in accordance with the present invention into a multilayer product, it is preferable only to apply the additive composition to one side of the tissue web, and then creped the treated side of the tissue web. The creped side of the web is then used to form the outer surface of the multilayer product. The untreated and uncreated sides of the web, on the other hand, are attached by any suitable means to one or more folds.

For example, referring to FIG. 8, one embodiment of a process for applying an additive composition to only one side of a tissue web in accordance with the present invention is shown. The process shown in FIG. 8 is similar to the process shown in FIG. 4. In this regard, similar reference numerals have been used to refer to like elements.

As shown, the web 80 is moved to the place of application of the additive composition, generally indicated at 98. Workstation 98 includes a transfer roller 100 in contact with the rotogravure roller 102, which is in communication with the reservoir 104 containing the additive composition 106. At the workstation 98 the additive composition 106 is applied to one side of the web 80 in the form of a pre-selected pattern.

When the additive composition is applied, the web 80 is adhesively attached to the creping roller 108 by means of a pressing roller 110. The web 80 is transferred to the surface of the creping drum 108 throughout and then removed from it by the action of the creping knife 112. The creping knife 112 performs the operation of creping the guided pattern onto the processed surface of the canvas.

From the creping drum 108, the tissue web 80 is passed through a drying station 114, where the additive composition 106 is dried and cured. The web 80 is then wound onto a roll 116 for use in forming multilayer products or a single layer product.

Referring to Fig. 36, another embodiment of a process for applying an additive composition to only one side of a tissue web in accordance with the present invention is shown. The same reference numbers were used to indicate the same elements.

The process shown in FIG. 36 is similar to the process shown in FIG. In the process shown in FIG. 36, however, the additive composition is applied directly to the tissue web 80 using an offset printing apparatus in an offset printing configuration.

For example, as shown in FIG. 36, the additive composition 106 is first transferred to the first printing roller 102. From the printing roller 102, the additive composition is then transferred to the analog roller 103 before being applied to the tissue web 80. From the analog roller 103, the additive composition is extruded onto the tissue web 80 using a rubber backup roll 100.

Similarly to FIG. 8, when the additive composition is applied to the tissue web 80, the web is then adhesively attached to the heated creping drum 108 and creped from the drum using a creping knife 112 before being rolled into a roll 116.

Referring to FIG. 37, another embodiment of a process for applying an additive composition to only one side of a tissue web in accordance with the present invention is shown. As shown, in this embodiment, the formed tissue web 80 is unwound from the roll 85 and fed into the process. This process can be considered as an auxiliary process, although the method of application can also be carried out directly in the process.

As shown in FIG. 37, the dried tissue web 80 is pressed onto the dryer drum 108 using a compression roller 110. The spray device 109 applies the additive composition of the present invention to the surface of the dryer drum. The additive composition thus not only adhesive adheres the tissue web 80 to the surface of the dryer drum 108, but is also transferred to the tissue tissue when the tissue web is creped from the drum using a creping knife 112. The creping field from the dryer drum 108 is wound onto a roll 80 116.

The embodiment shown in FIG. 37 may involve the use of a spray creping process. In this process, the dryer drum 108 may be heated to temperatures that are described above with respect to other embodiments shown in the drawings.

When treating only one side of the tissue web 80 with an additive composition, in one embodiment, it may be desirable to apply the additive composition in accordance with a pattern that covers more than about 40% of the surface area of one side of the canvas. For example, a pattern may cover from about 40% to about 90% of the surface area of one side of the web, such as from about 40% to about 60%. In one specific example, for example, the additive composition may be applied in accordance with the pattern shown in FIG. 7.

In one particular embodiment of the present invention, a two-layer product is formed from a first paper web and a second paper web, in which both paper webs are generally made in accordance with the process shown in FIG. For example, a first paper web made in accordance with the present invention can be attached to a second paper web made in accordance with the present invention, so that the creped sides of the web form the outer surfaces of the final product. Crepe surfaces are generally softer and smoother to form a two-layer product having improved overall properties.

The manner in which the first paper web is laminated to the second paper web can vary depending on the particular application and desired properties. In some applications, the alpha olefin interpolymer of the present invention can serve as a layer bonding agent. In other applications, a binder material, such as adhesive or binder fibers, is applied to one or both webs to bond the webs together. The adhesive, for example, may be a latex adhesive, a starch-based adhesive, an acetate adhesive such as ethylene-vinyl acetate adhesive, a polyvinyl alcohol adhesive, and the like. It should be understood, however, that other binders, such as thermoplastic films and fibers, can also be used to join the webs. Binder material can be sprayed evenly over the surfaces of the web to firmly bond the web together, or it can be applied at selected locations.

It should be understood that in addition to the wet laying processes shown in FIGS. 2 and 3, various other base sheets can be processed in accordance with the present invention. For example, other base sheets that can be processed in accordance with the present invention include sheets laid in the air flow, co-forming webs and hydraulically entangled webs. When processing this type of base sheet, the additive composition is generally applied superficially to these base sheets. For example, the additive composition may be sprayed or printed onto the surface of the base sheet.

Cloths laid in the air stream are formed during molding by air, in which a fibrous nonwoven layer is formed. In the process of laying in an air stream, bundles of small fibers having a normal length in the range of from about 3 to about 52 millimeters (mm) are separated and placed to an air supply, and then distributed on a forming mesh, usually by applying a vacuum. Randomly distributed fibers are then bonded to each other using, for example, hot air or spraying adhesive. The production of nonwoven composites laid in the air stream is well described in the literature and in the documents of the prior art. Examples include the DanWeb process, which is described in US Pat. No. 4,640,810 to Laursen et al., And referred to Scan Web of Northe America Inc., the Croer process, which is described in US Pat. No. 4,494,278, Crower et al., And in US Pat. No. 5,527,171. Soerensen, referred to Niro Separation a / s, US Pat. No. 4,375,448, Appel, transferred to Kimberly-Clark Corporation, or other similar methods.

Other materials containing cellulosic fibers include co-forming webs and hydraulically entangled webs. In co-molding processes, at least one extrusion die for blow molding is located near the trough through which other materials are added to the meltblown web during molding. Such other materials may be natural fibers, superabsorbent particles, natural polymer fibers (e.g. viscose) and / or artificial polymer fibers (e.g. polypropylene or polyester), for example when the fibers can be staple length.

Co-molding processes are shown in U.S. Patent Nos. 4,818,464, Lau and 4,100,324, Anderson et al., All of which are incorporated herein by reference. Products produced through a co-molding process are generally referred to as co-molding materials. More specifically, one process for the production of co-molded non-woven webs includes extruding the molten polymer material through an extrusion die into thin streams and disrupting the streams by converging high-speed streams of heated gas (usually air) from nozzles to break the polymer streams to form intermittent microfibres of small diameter. The extrusion head, for example, may include at least one straight row of extrusion holes. In general, microfibers can have an average fiber diameter of up to about 10 microns. The average diameter of the microfibers can be generally greater than about 1 micron, such as from about 2 microns to about 5 microns. Although microfibers are predominantly discontinuous, they generally have a length greater than the length usually associated with staple fibers.

To combine molten polymer fibers with another material, such as pulp fibers, the primary gas stream is combined with a secondary gas stream containing individual wood pulp fibers. Thus, the pulp fibers become integrated with the polymer fibers in a single step. Wood pulp fibers may have a length of from about 0.5 mm to about 10 mm. The integrated air flow is then directed to the forming surface to form non-woven material with air. The nonwoven material, if desired, may extend into a clamp consisting of a pair of vacuum rolls to further integrate two different materials.

Natural fibers that can be combined with meltblown fibers include wood, cotton, flax, hemp, and wood pulp. Wood pulps include standard varieties of softwood with a hairy appearance, such as CR-1654 (US Alliance Pulp Mills, Coosa, Alabama). The pulp can be modified to improve the natural properties of the fibers and their ability to process. The fibers can be twisted using methods including chemical treatment or mechanical twisting. Torsion is usually imparted before crosslinking or imparting strength. Pulp can be strengthened by using crosslinking agents such as formaldehyde or its derivatives, glutaraldehyde, epichlorohydrin, oxymethylated compounds such as urea or urea derivatives, dialdehydes such as maleic anhydride, unoxymethylated urea derivatives, citric acid or other polycarboxylic acids. The pulp can also be given strength by using heat or caustic treatment, such as mercerization. Examples of these types of fibers include NHB416, which is a chemical cross-linking soft southern wood pulp fiber that improves wet modulus available from Weyerhaeuser Corporation, Tacoma, WA. Other pulps used are non-adherent pulp (NF405) and non-adherent pulp (NB416), also available from Weyerhaeuser. HPZ3 from Buckeye Technologies, Inc., Memphis, TN has a chemical treatment that cures by imparting twisting and twisting in addition to giving the fibers extra wet and dry strength and elasticity. Another suitable pulp is Buckeye HP2 and another is IP Supersoft from International Paper Corporation. Suitable viscose fibers are 1.5 denier fibers of Merge 18453 from Acordis Cellulose Fibers Incorporated, Axis, Alabama.

When containing cellulosic materials such as pulp fibers, the co-molding material may contain cellulosic material in an amount of from about 10 wt.% To about 80 wt.%, Such as from about 30 wt.% To about 70 wt.%. For example, in one embodiment, co-molding material may be produced comprising pulp fibers in an amount of from about 40 wt.% To about 60 wt.%.

In addition to co-forming webs, hydraulically entangled webs may also contain synthetic fibers and pulp fibers. Hydraulically entangled webs refer to webs that have been exposed to columnar jets of fluid that cause the fibers to become entangled. Hydraulic entanglement of the web usually increases the strength of the web. In one embodiment, the pulp fibers can be hydraulically entangled into a continuous fibrous material, such as spunbond material. The resulting non-woven composite material may contain pulp fibers in an amount of from about 50 wt.% To about 80 wt.%, Such as, for example, in an amount of about 70 wt.%. Commercially available hydraulically entangled composite webs as described above are webs from Kimberly-Clark Corporation under the name HYDROKNIT. Hydraulic entangling is described, for example, in US Pat. No. 5,389,202 to Everhart, which is incorporated herein by reference.

The present invention may be better understood with reference to the following examples.

EXAMPLE 1

To show the properties of the tissue products made in accordance with the present invention, various tissue samples were treated with the additive composition and subjected to standardized tests. For comparison, untreated tissue samples, tissue samples treated with a silicone composition, and tissue samples treated with an ethylene vinyl acetate binder were also tested.

More specifically, the tissue samples contained tissue sheets containing three layers. Each layer of a three-layer tissue sample was formed in a process similar to the process of FIG. 3. Each layer had a base weight of about 13.5 g / sq. M. More specifically, each layer was made of a hardened fiber composition containing a central layer of fibers located between two outer layers of fibers. The outer layers of each layer contained eucalyptus kraft pulp obtained from Aracruz, offices in Miami, FL, USA. Each of the two outer layers accounted for approximately 33% of the total weight of the sheet fibers. The central layer, which accounted for 34% of the total weight of the leaf fibers, consisted of 100% soft northern wood kraft pulp obtained from Neenah Paper Inc., offices in Alpharetta, GA, USA. Three layers were bonded together so that the sides of the napkin were pressed on a drying device facing the outer surfaces of the three-layer tissue sample.

Three-layer tissue sheets were coated with additive compositions made in accordance with the present invention. A second set of samples was coated with a silicone composition, while a third set of samples was coated with an ethylene vinyl acetate copolymer.

Tissue sheets were coated with the above compositions using rotogravure printing. A tissue web was fed into a rubber-rubber clamp of a rotogravure printing device for applying the above compositions to both sides of the web. The intaglio rolls (engraving rolls) were electronically engraved rolls coated with chromium and copper, supplied by Specialty Systems, Inc., Louisville, Ky. The rolls had a linear raster of 200 cells per linear inch and a volume of 8.0 billion cubic microns (HSR) per square inch of roll surface. The usual cell sizes for this roll were 140 microns in width and 33 microns in depth, using an engraving cutter at an angle of 130 degrees. Offset rubber back-up rolls were a polyurethane form with Shore A hardness of 75 from Amerimay Roller Company, Uninon Grove, Wisconsin. The process was carried out under the condition that 0.375 inches of interaction between the engraving rolls and the rubber backup rolls and a gap of 0.003 inch between the rubber coated backup rolls was ensured. The simultaneous offset / offset engraving printing apparatus operated at a speed of 150 feet per minute using the speed (differential) control of the engraving roll to measure the above composition in order to obtain the desired addition speed. The process provided an addition level of 6% by weight of the total addition based on the weight of the wipe (3.0% on each side).

For samples treated with an additive composition prepared in accordance with the present invention, the following table discloses the components of the additive composition for each sample. In the table below, the AFFINITY ™ EG8200 plastomer is an alpha olefin interpolymer containing a copolymer of ethylene and octene, which was purchased from The Dow Chemical Company of Midland, Michigan, USA. The PRIMACOR ™ 5980i copolymer is a copolymer of ethylene and acrylic acid, also purchased from The Dow Chemical Company. A copolymer of ethylene and acrylic acid can serve not only as a thermoplastic polymer, but also as a dispersing agent. INDUSTRENE® 106 contains oleic acid, a product distributed by Chemtura Corporation, Middlebury, Connecticut. The polymer designated as “PBPE” is an experimental propylene-based plastomer or elastomer (“PBPE”) having a density of 0.867 g / cm ³ as measured in accordance with ASTM D792, melt flow rate of 25 g / 10 minutes at 230 ° C, at 2.16 kg, as measured in accordance with ASTM D 1238, and an ethylene content of 12% by weight of PBPE. From the international publication WO 03/040442 and US patent application 60/709688 (filed August 19, 2005), each of which is incorporated herein by reference in its entirety, these substances are known to be PBPEs. The AFFINITY ™ PL1280 Plastomer is an alpha olefin interpolymer containing a copolymer of ethylene and octene, which is also available from The Dow Chemical Company. The UNICID® 350 dispersant is a surfactant whose functional part is linear primary carboxylic acid and the hydrophobic part contains an average of 26 carbon atoms. This dispersant was purchased from Baker-Petrolite Inc., Sugar Land, Texas, USA. AEROSOL® OT-100 Dispersant is dioctyl sodium sulfosuccinate purchased from Cytec Industries, Inc., West Paterson, New Jersey, USA. The PRIMACOR ™ 5980i copolymer contains 20.5 wt.% Acrylic acid and has a melt flow rate of 13.75 g / 10 min at 125 ° C and 2.16 kg, as measured in accordance with ASTM D1238. The AFFINITY ™ EG8200G plastomer has a density of 0.87 g / cm ³ as measured in accordance with ASTM D792, and has a melt flow rate of 5 g / 10 min at 190 ° C. and 2.16 kg, as measured in accordance with ASTM D1238. The AFFINITY ™ PL1280G plastomer, on the other hand, has a density of 0.90 g / cm ³ as measured in accordance with ASTM D792, and has a melt flow rate of 6 g / 10 min at 190 ° C. and 2.16 kg, as measured in accordance with ASTM D1238 .

The additive composition in each of the samples also contained the DOWICIL ™ 200 antimicrobial product purchased from The Dow Chemical Company, which is a preservative supplemented with 96% cis 1- (3-chlorallyl) -3,5,7-triaz-1 -azoniaadamantane chloride (also known as Quaternium-15).

Sample No Polymer (weight ratio in parentheses) Dispersant Dispersant, conc. (the weight%) one AFFINITY ™ EG8200 Unicid® 350 3.0 2 AFFINITY ™ EG8200 / PRIMACOR ™ 5980i (70/30) PRIMACOR ™ 5980i 30.0 3 PBRE Unicid® 350 / AEROSOL® OT-100 3.0 / 2.5 four PBPE / PRIMACOR ™ 5980i (70/30) PRIMACOR ™ 5980i 30.0 5 AFFINITY ™ EG8200 / AFFINITY ™ PL1280 (80/20) Unicid® 350 / Industrene® 106 2.0 / 2.0 6 AFFINITY ™ EG8200 / AFFINITY ™ PL1280 (50/50) Unicid® 350 / Industrene® 106 2.0 / 2.0 7 AFFINITY ™ EG8200 / PRIMACOR ™ 5980i (75/25) PRIMACOR ™ 5980i / Industrene® 106 25.0 / 3.0 8 AFFINITY ™ EG8200 / PRIMACOR ™ 5980i (90/10) PRIMACOR ™ 5980i 10.0 9 AFFINITY ™ EG8200 / PRIMACOR ™ 5980i (75/25) PRIMACOR ™ 5980i / Industrene® 106 25.0 / 3.0 10 AFFINITY ™ EG8200 / PRIMACOR ™ 5980i (60/40) PRIMACOR ™ 5980i / Industrene® 106 40.0 / 6.0 eleven AFFINITY ™ EG8200 / PRIMACOR ™ 5980i (75/25) PRIMACOR ™ 5980i / Industrene® 106 25.0 / 3.0 12 AFFINITY ™ EG8200 / PRIMACOR ™ 5980i (90/10) PRIMACOR ™ 5980i / Industrene® 106 10.0 / 6.0 13 AFFINITY ™ EG8200 / PRIMACOR ™ 5980i (90/10) PRIMACOR ™ 5980i 10.0 fourteen AFFINITY ™ EG8200 / PRIMACOR ™ 5980i (60/40) PRIMACOR ™ 5980i / Industrene® 106 40.0 / 6.0 fifteen AFFINITY ™ EG8200 / PRIMACOR ™ 5980i (75/25) PRIMACOR ™ 5980i / Industrene® 106 25.0 / 3.0 16 AFFINITY ™ EG8200 / PRIMACOR ™ 5980i (90/10) PRIMACOR ™ 5980i 10.0 17 AFFINITY ™ EG8200 / PRIMACOR ™ 5980i (75/25) PRIMACOR ™ 5980i / Industrene® 106 25.0 / 3.0 eighteen AFFINITY ™ EG8200 / PRIMACOR ™ 5980i (90/10) PRIMACOR ™ 59801 / Industrene® 106 10.0 / 6.0 19 AFFINITY ™ EG8200 / PRIMACOR ™ 5980i (60/40) PRIMACOR ™ 5980i 40.0 twenty AFFINITY ™ EG8200 / PRIMACOR ™ 5980i (60/40) PRIMACOR ™ 5980i 40.0 21 AFFINITY ™ EG8200 / PRIMACOR ™ 5980i (60/40) PRIMACOR ™ 5980i / Industrene® 106 40.0 / 6.0

Sample No The particle size of the polymer (μm) Polydispersity Solids (weight%) pH Viscosity (cP) Pace. ° C Rpm Spindle one 1.08 1.83 54.7 10.0 83 22 fifty RV2 2 1.48 2.40 41.0 10.5 338 twenty fifty RV3 3 0.72 1.42 55.5 10.2 626 21.1 fifty RV3 four 0.85 2.06 42.8 10.2 322 21.5 fifty RV3 5 0.86 1.68 55.2 9.7 490 55.0 fifty RV3 6 1.08 1.85 52.4 10.9 296 21.7 fifty RV3 7 1.86 4.46 50.1 9.4 538 21.1 fifty RV3 8 5.55 2.67 49.3 9.0 <75 21.6 one hundred RV3 9 1.18 2.48 46.1 10.5 270 21.2 fifty RV3 10 1.60 1.58 41.1 8.7 368 21.7 fifty RV3 eleven 1.69 3.68 48.8 9.7 306 22.1 fifty RV3 12 1.34 2.24 51.0 10.2 266 21.4 fifty RV3 13 1.16 2.25 46.6 10.5 85 21.5 one hundred RV3 fourteen 1.01 1.57 32.1 10.3 572 21.7 fifty RV3 fifteen 1.53 3.50 50.1 9.9 396 22.3 fifty RV3 16 9.86 4.14 51.2 8.7 <75 21.5 fifty RV3 17 1.57 3.26 49.8 9.9 436 22.4 fifty RV3 eighteen 0.89 1.51 51.1 12.3 342 21.5 fifty RV3 19 0.71 2.12 40.0 11.3 448 22.1 fifty RV3 twenty 1.63 2.23 42.0 8.6 178 22.0 one hundred RV3 21 1.49 1.87 39.0 10.3 210 20.2 fifty RV3

For comparison, the following samples were also prepared:

SAMPLE COMPOSITION APPLIED ON SAMPLE Sample No. 1 not according to the invention Unprocessed Sample No. 2 not according to the invention Product No. Y-14868, emulsified silicone obtained from G. E. Silicones Sample No. 3 not according to the invention AIRFLEX (R) 426 Carboxylated Terpolymer Emulsion Binder vinyl acetate and ethylene obtained from Air Products, Inc. Sample No. 4 not according to the invention ELVAX (R) 3175 a binder containing an ethylene vinyl acetate copolymer obtained from E. I. DuPont de Nemours of Wilmington, Delaware, having a 28% vinyl acetate content. The vinyl acetate copolymer was combined with UNICID 425, which is a hydrophobic functionalized carboxylic acid surfactant containing a middle 32-carbon chain obtained from Baker-Petrolite, Inc. of Sugarland, Texas

The following tests were performed on the samples.

Tensile strength, geometric mean tensile strength (GMT) and geometric mean absorbed energy at break (GMTEA)

The tensile test was carried out using tissue samples under conditions of 23 ° C +/- 1 ° C and 50% +/- 2% relative humidity for 4 hours. Bilayer samples were cut into 3 inch strips in the machine direction (MN) and the transverse machine direction (PN) using a precision sample cutter, model JDC 15M-10, obtained from Thwing-Albert Instruments, with an office located in Philadelphia, Pennsylvania, USA

The base measuring length of the stretch frame was 4 inches. The stretch frame was an Alliance RT / 1 frame working with TestWorks 4 software. Tensile frame and software are available from MTS Systems Corporation, a company office in Minneapolis, Minnesota, U.S.A.

A 3-inch strip was then placed in the cams of the tensile frame and subjected to tensile force applied at a speed of 25.4 cm per minute to the point of damage to the sample. The stress on the swipe strip was shown as a function of tensile force. The calculated results included peak load (gram-force / 3 inches, measured in gram-force), peak elongation (% calculated by dividing the elongation of the sample by the original length of the sample and multiplied by 100%),% tension @ 400 gram-force, absorption energy (TEA) in case of damage (gram-force × cm / cm ² calculated by integration or taking the area under the stress-tension curve to the point of damage, where the load drops to 30% of its peak value) and slope A (kilogram-force measured as the slope of the voltage-tension curve from 57-150 gram-forces s).

Each group of napkins (at least five repetitions) was tested in the machine direction (MN) and the transverse machine direction (PN). The geometric mean tensile strength and energy absorption at break (TEA) was calculated as the square root of the product in the machine direction (MN) and the transverse machine direction (PN). From this, an average value was obtained that does not depend on the direction of testing. The samples used are shown below.

Elastic modulus (Maximum slope) and geometric mean modulus (GMM), as a measurement of sheet strength

The modulus of elasticity (Maximum slope) E (kg _s ) is the modulus determined in the dry state and is expressed in units of kilogram-force. Samples treated in accordance with TAPPI conditions, a width of 3 inches were placed in the cams for tensile testing with a basic measuring length (distance between the cams) of 4 inches. The cams moved from each other at a lateral speed of 25.4 cm / min and the slope was taken using the least squares method between the voltage values of 57 gram-force and 150 gram-force. If the sample is too weak to withstand a voltage of at least 200 gram forces without damage, an additional layer is re-added until the multilayer sample can withstand at least 200 gram forces without damage. The geometric mean modulus or geometric mean slope was calculated as the square root of the elastic moduli (maximum slopes) of the product in the machine direction (MN) and in the transverse machine direction, obtaining an average value that does not depend on the direction of the test.

The test results are graphically shown in FIGS. 9-14. As shown by these results, the additive composition of the present invention improved the geometric mean tensile strength without significantly affecting the stiffness of the sheet compared to the untreated sample and the sample treated with the silicone composition. In addition, the ratio of the geometric mean of the modulus to the geometric mean of the gap for samples treated with an additive composition made in accordance with the present invention showed similar properties compared to a sample treated with a binder of an ethylene vinyl acetate copolymer. It was noted, however, that the blocking properties of the sheet in the samples treated with the additive composition were much better compared to the sample treated with the ethylene vinyl acetate copolymer.

In addition to the results shown in the drawings, softness tests were also performed on the samples. The perceptible softness of the samples treated with the additive composition of the present invention was equivalent to the perceptibly softness of the samples treated with the silicone composition.

EXAMPLE 2

In this example, additional compositions made in accordance with the present invention were printed onto a non-creped, dried through-air stream (UCTAD) main web in accordance with a pattern and creped from a creping drum. The additive composition was used to adhere the main web to the drum. The samples were then tested and compared with a non-creped main web dried in a through air flow that was not subjected to a creping process (Sample No. 1 not according to the invention) and with an uncreated main web dried in a continuous air flow that had been subjected to a similar creping process using ethylene vinyl acetate copolymer (Sample No. 2 not according to the invention).

An uncreated, main web-dried web was formed in a process similar to that shown in FIG. 2. The base sheet had a base weight of about 50 g / m2. More specifically, the base sheet was made of a hardened fiber composition containing a central layer of fibers located between two outer layers of fibers. Both outer layers of the main sheet contained 100% kraft pulps of northern softwood. One outer layer contained about 10.0 kilograms (kg) / metric ton (mt) of dry fiber disintegrant (ProSoft (R) TQ1003 from Hercules, Inc.). The other outer layer contained about 5.0 kg / mt of dry fiber material for dry and wet strength (KYMENE (R) 6500 from Hercules, Incorporated, Wilmington, Delaware, U.S.A.). Each of the outer layers contained about 30% of the total weight of the leaf fibers. The central layer, which contained about 40% of the total weight of the leaf fibers, consisted of 100 wt.% Kraft, pulp of soft northern wood species. The fibers in this layer were also treated with 3.75 kg / mt of ProSoft (R) TQ1003 disintegrant.

Various samples of the base sheet were then subjected to a creping printing process. The creping printing process is generally shown in FIG. The sheet was planted to the line of engraving printing, where the additional composition was applied by printing on the surface of the sheet. One side of the sheet was printed using direct rotogravure printing. The sheet was printed with a “dot” pattern, with a diameter of “dots” of 0.020, as shown in FIG. 5, where 28 dots per inch were printed on the sheet in both machine and transverse machine directions. The resulting surface area coating was about 25%. The sheet was then pressed and removed from the rotary drum, causing a change in sheet temperature in the range from about 180 ° F. to about 390 ° F., such as from about 200 ° F. to 250 ° F. Finally, the sheet was coiled. Then, the resulting print / seal / creped sheet was converted into rolls of single layer towel paper in a conventional manner. The finished product had an air dry basis weight of approximately 55.8 g / m2

As described above, for comparative purposes, one sample was subjected to a similar creping process using an AIRFLEX® 426 binder from Air Products, Inc., Allentown, PA. AIRFLEX® 426 is a cross-linked, flexible, carboxylated vinyl acetate ethylene triple polymer emulsion.

Additional compositions that have been applied to various samples are shown in the following tables. In the AFFINITY ™ EG8200 tables, the plastomer contains an ethylene-octene copolymer interpolymer, while the PRIMACOR ™ 598Oi contains an ethylene-acrylic acid copolymer. INDUSTRENE®106 contains oleic acid. All three components were obtained from The Dow Chemical Company.

Sample No Polymer (weight ratio in parentheses) Dispersant Dispersant, conc. (the weight.%) one AFFINITY ™ EG8200 / PRIMACOR ™ 5980i (60/40) PRIMACOR ™ 5980i / Industrene® 106 40.0 / 6.0 2 AFFINITY ™ EG8200 / PRIMACOR ™ 5980i (60/40) PRIMACOR 5980i ™ / Industrene® 106 40.0 / 6.0 3 AFFINITY ™ EG8200 / PRIMACOR ™ 5980i (60/40) PRIMACOR 5980i ™ 40.0 four AFFINITY ™ EG8200 / PRIMACOR ™ 5980i (60/40) PRIMACOR 5980i ™ 40.0

Sample No The particle size of the polymer (μm) Polydispersity Solids (wt.%) pH Viscosity (cP) Pace. ° C Rpm Spindle one 1.60 1.58 41.1 8.7 368 21.7 fifty RV3 2 1.01 1.57 32.1 10.3 572 21.7 fifty RV3 3 0.71 2.12 40.0 11.3 448 22.1 fifty RV3 four 1.63 2.23 42.0 8.6 178 22.0 one hundred RV3

The DOWICIL ™ 200 antimicrobial product, which is a preservative supplemented with 96% cis 1- (3-chlorallyl) -3,5,7-triaz-1-azoniaadamantane chloride (also known as Quaternium-15), obtained from The Dow Chemical Company is also present in each of the additional compositions.

Samples were subjected to the tests described in Example 1. In addition, the following test was also performed on the samples.

Wet / dry tensile test (% in transverse machine direction)

The dry tensile test in Example 1 with a basic measuring length (cam distance) of 2 inches. The tensile strength in the wet state was measured in the same manner as the dry strength, except that the samples were wetted before testing. More specifically, to moisten a sample, a 3X5-inch tray was filled with distilled or deionized water at a temperature of 23 +/- 2 ° C. Water was added to the tray to a depth of approximately one centimeter.

The Scotch-Brite universal abrasive pad (skin) was then cut into 2.5 × 4 inches. An insulating tape approximately 5 inches long was placed along the edges of the 4 inch pad. An insulating tape was used to hold the abrasive pad.

The abrasive pad was then placed in water with tape-wound ends facing up. The pad remained in the water all the time until the test was completed. The sample to be tested was placed on blotting paper that complies with TAPPI T205. The abrasive pad was removed from the container with water and slightly incised three times on a grid connected to a moisturizing tray. The abrasive pad was then neatly placed on the sample parallel to the width of the sample, approximately in the center. The abrasive pad was held in place for approximately one second. The sample was then immediately placed in a tensile tester and tested.

To calculate the tensile strength in the wet / dry state, the value of tensile strength in the wet state was divided by the value of tensile strength in the dry state.

The results obtained are shown in Fig.15-19. As shown in the drawings, the additive compositions improved the geometric mean value of the gap and the geometric mean value of the total absorbed energy of the tissue samples without significantly affecting the stiffness of the sheet relative to the untreated samples. Also during the testing process, it was found that the additive compositions did not create problems with blocking of the sheets compared to samples treated with a copolymer of ethylene vinyl acetate.

Example 3

In this example, tissue webs were made generally in accordance with the process shown in FIG. 3. In order to adhesively adhere the tissue sheet to the creping surface, which in this embodiment is a Yankee dryer, an additive composition made in accordance with the present invention was sprayed onto the dryer before the dryer was contacted with the canvas. Samples were then subjected to various standardized tests.

For comparison, samples were also produced using standard crepe packaging PVOH / KYMENE.

In this example, two-layer tissue products were manufactured and tested in accordance with the same tests as described in Examples 1 and 2. The following process was used to produce samples.

First, 80 pounds of air-dried softwood kraft pulp (NSWK) was placed in a pulper and separated for 15 minutes at a density of 4% and at 120 ° F. Then, the NSWK pulp was cleaned for 15 minutes, transferred to a mass pool and subsequently diluted to a consistency of about 3% (note: purification fibrillated fibers to increase the possibility of their connection). The NSWK pulp was then diluted to a consistency of about 2% and pumped into the machine pool, so that the machine pool contained 20 pounds of dried NSWK pulp with a consistency of about 0.2-0.3%. The aforementioned softwood fibers were used as an inner strong layer in a three-layer tissue structure.

Two kilograms of KYMENE®, available from Hercules Incorporated, Wilmington, Delaware, USA, per metric ton of wood fiber and two kilograms per metric ton of wood fiber PAREZ® 631 NC, available from LANXESS Corporation, Trenton, New Jersey, USA, were added for mixing with pulp fibers for at least ten minutes before feeding the pulp suspension through the headbox.

Forty pounds of air-dried Aracruz ECF kraft pulp of eucalyptus hardwood (EHWK), available from Rio de Janeiro, RJ, Brazil, was placed in a pulper and separated for 30 minutes at a density of 4% and at 120 ° F. Then the EHWK pulp was transferred to the mass pool and subsequently liquefied to a consistency of about 2%.

The EHWK pulp was then diluted, divided into two equal amounts, and pumped at a consistency of 1% into two separate machine pools, so that each machine pool contained 20 pounds of dried EHWK pulp. This pulp suspension was subsequently diluted to a consistency of about 0.1%. Two pulp fibers represent two outer layers of a three-layer tissue structure.

Two kilograms of KYMENE® 6500 per metric ton of wood fiber was added and allowed to mix with hardwood pulp fibers for at least 10 minutes before the pulp slurry was pumped through the headbox.

Pulp fibers from all three engine pools were pumped to the headbox at a consistency of about 0.1%. The pulp fibers of each machine pool passed through separate manifolds in the headbox to create a three-layer tissue structure. Fibers were placed on the molding material. The water was then sequentially removed using vacuum.

A wet sheet with a consistency of about 10-20% was transferred to a pressing felt material or a pressing material, where it was further dehydrated. The sheet is then transferred to a Yankee tumble dryer through a clamp by means of a press roll. The wet sheet consistency after clamping the press roll (consistency after the press roll or PPRC) was approximately 40%. The wet sheet was adhesively adhered to the Yankee dryer due to the adhesive that is applied to the surface of the dryer. The spray booms located below the Yankee dryer were sprayed with either adhesive, which was a mixture of polyvinyl alcohol / KYMENE® / REZOSOL 2008M, or an additive composition as described herein onto the surface of the dryer. REZOSOL 2008M is available from Hersules, Incorporated, based in Wilmington, Delaware, USA.

One serving of conventional adhesive on a continuous manual cast sheet (CHF) forming machine typically consists of 25 gallons of water, 5000 ml of polyvinyl alcohol solution with 6% solids, 75 ml of KYMENE® solution with 12.5% solids, and 20 ml of Rezosol solution 2008M with 7.5% solids.

In the additional compositions in accordance with the present invention, the solids content varied from 2.5% to 10%.

The sheet was dried to a consistency of about 95% when it was transported on a Yankee dryer and to a creping knife. The creping knife then removes the tissue sheet and a small amount of the coating of the drying apparatus from the Yankee drying apparatus. The creped main tissue sheet was then wound onto a 3 inch core to form soft rolls for conversion. The two rolls of creped napkins were then rewound and folded together so that both creped sides were on the outer sides of the two-layer structure. Mechanical compression at the edges of the structure holds the layers together. The laminated sheet was then cut at the edges to a standard width of approximately 8.5 inches and folded. Tissue samples were placed under certain conditions and tested.

The additive compositions of the present invention that were applied to the samples and tested in this example are as follows.

Sample No Polymer (weight ratio in parentheses) Dispersant Dispersant, conc. (the weight.%) % Solids one AFFINITY ™ EG8200 / PRIMACOR ™ 5980i (60/40) PRIMACOR ™ 5980i / Industrene® 106 40.0 / 6.0 2.5 2 AFFINITY ™ EG8200 / PRIMACOR ™ 5980i (60/40) PRIMACOR ™ 5980i 40.0 2.5 3 AFFINITY ™ EG8200 / PRIMACOR ™ 5980i (60/40) PRIMACOR ™ 5980i / Industrene® 106 40.0 / 6.0 5 four AFFINITY ™ EG8200 / PRIMACOR ™ 5980i (60/40) PRIMACOR ™ 5980i 40.0 5 5 AFFINITY ™ EG8200 / PRlMACOR ™ 5980i (60/40) PRIMACOR ™ 5980i / Industrene® 106 40.0 / 6.0 10

Sample No The particle size of the polymer (μm) Poly dispersion Solids (wt.%) pH Viscosity (cP) Pace. ° C Rpm Spindle one 1.01 1.57 32.1 10.3 572 21.7 fifty RV3 2 0.71 2.12 40.0 11.3 448 22.1 fifty RV3 3 1.01 1.57 32.1 10.3 572 21.7 fifty RV3 four 0.71 2.12 40.0 11.3 448 22.1 fifty RV3 5 1.01 1.57 32.1 10.3 572 21.7 fifty RV3

The DOWICIL ™ 200 antimicrobial product, which is a preservative supplemented with 96% cis 1- (3-chlorallyl) -3,5,7-triaz-1-azoniaadamantane chloride (also known as Quaternium-15), obtained from The Dow Chemical Company is also present in each of the additional compositions.

As shown above, the percentage of solids in solution for various additive compositions varied. A change in the solids content of the solution also changes the amount of solids included in the base web. For example, with a solids content of 2.5%, it was found that from about 35 kg / mt to about 60 kg / mt of solids is included in the tissue web. When the content of 5% solids in the solution, it was found that from about 70 kg / MT to about 130 kg / MT is included in the tissue. With a content of 10% solids in the solution, it was found that from about 140 kg / mt to about 260 kg / mt of solids is included in the tissue.

The results of this example are shown in FIGS. 20-24. As shown in FIG. 20, for example, the geometric mean tensile strength of samples made in accordance with the present invention was higher than for non-invention samples treated with a traditional binder material. Similar results were also obtained for the geometric mean total absorbed energy.

In addition to testing sample properties, some samples were also photographed. For example, referring to FIGS. 25A, 25B, 25C, and 25D, four samples are shown magnified 500 times. Figv is a photograph of sample No. 1, Fig.25c is a photograph of sample No. 3, and Fig. 25B is a photograph of sample No. 5. As shown, the additive composition of the present invention seeks to form an intermittent film on the surface of the tissue web. In addition, the higher the solids content in the solution, the higher the film formation value. These drawings show that the additive composition generally remains on the surface of the tissue web.

Referring to FIG. 26, a cross-sectional photograph of the same sample as shown in FIG. 25B is shown. As can be seen in the photograph, even with a 10% solids content in solution, most of the additive composition penetrates the web in an amount less than about 25% of the thickness of the web, such as less than about 15% of the thickness of the web, such as less than about 5% of the thickness canvases.

Thus, it is believed that the additive composition provides a sufficient amount of strength for the tissue web. In addition, since the film is intermittent, the absorbent properties of the web are essentially not adversely affected. It is particularly preferred that these results are also obtained without substantially increasing the rigidity of the tissue web and without significantly reducing the perceived softness.

Example 4

In this example, tissue webs made in accordance with the present description were compared with commercially available products. Samples were subjected to various tests. More specifically, the samples were subjected to the stick-slip test, which measures the perceived softness of the product by measuring the spatial and temporal changes in the pulling force when the skin simulator is pulled over the surface of the sample.

More specifically, the following tests were performed in this example.

Adhesion-slip test

Stick-slip occurs when the static coefficient of friction (COF) is significantly higher than the kinetic COF. The slide that is pulled along the surface with a rope will not move until the force in the rope is high enough to overcome the static COF multiplied by the normal load. However, as soon as the sled begins to move, static COF gives way to a lower kinetic COF, so that the pulling force in the rope is unbalanced and the sled is accelerated until the tension in the rope is released and the sled stops (sticks). The tension then builds up again until it is high enough to overcome static COF, etc. The frequency and amplitude of the oscillations depends on the difference between static COF and kinetic COF, as well as on the length and stiffness of the rope (a rigid short rope will allow the force to fall almost immediately when the static COF is overcome, so that the sled sharply jerks forward only a short distance) and the speed displacement. Higher speeds tend to lower the stick-slip property.

Static COF is higher than kinetic COF, since two surfaces in contact under load tend to slide and touch each other and increase the contact area between them. COF is proportional to the contact area, so the longer the contact time, the higher the COF. This helps explain why higher speeds provide lower stick-slip: there is less time after each stick to touch the surface and increase static COF. For many materials, COF decreases at a faster sliding rate because contact time is reduced. However, some materials (usually soft or greased surfaces) do exhibit an increase in COF with increasing speed, since the surfaces in contact tend to move either plastic or viscoelastic and dissipate energy at a rate proportional to the speed at which they move. Materials that have increased COF with increasing speed do not exhibit adhesion-sliding, since they require more force to push the slide forward than to continue moving at a constant lower speed. Such materials also have a static COF equal to their kinetic COF. Therefore, measuring the COF slope as a function of the velocity curve is a good predictor of whether the material is suitable for demonstrating adhesion-slippage: more negative inclinations will provide easier adhesion-slippage, while more positive inclinations will not adhere-slip even at very low sliding speed.

According to the stick-slip test, COF changes with sliding speed are measured using an Alliance RT / 1 tensile frame equipped with MTS TestWorks 4 software. A diagram of a portion of the test device is shown in FIG. 27. As shown, the plate is fixedly attached to the bottom of the frame, and a tissue sheet (sample) is attached to this plate. Aluminum skid with a flat surface of 1.5 inches by 1.5 inches with a radius ^of _1/2 inch on the leading and trailing edges are attached to the upper (moving part) frame using small scaffolding (30 feet of peeled Stren monofilament from Remington Arms Inc., Madison , NC) and lead to a pulling unit with almost no friction up to 50N load cell. A 50.8 mm wide collagen film sheet is flatly attached to the back of the slide by means of 32 mm connection clips on the front and rear sides of the slide. The total mass of the slide, film and clamps is 81.1 g. The film is larger than the slide, so that it completely covers the contact surfaces. A collagen film can be obtained from NATURIN Gmbh, Weinhein, Germany under the name COFFI (collagen food film) having a base weight of 28 g / sq. M. Another suitable film can be obtained from VIscofan USA Inc, 50 County Court, Montgomery AL 36105. The films are embossed by a small dot pattern. The flatter side of the film (with dots recessed down) should face down in the direction of the napkin on the sled to maximize the contact area between the napkin and collagen. Samples and collagen film should be at 72 ° F and 50% relative humidity for at least 6 hours before testing.

The tensile frame is programmed in order to pull the slide at a constant speed (V) over a distance of 1 cm, while the pulling force is measured at a frequency of 50 Hz. An average pull force measured between 0.2 cm and 0.9 cm is calculated and the kinetic coefficient of COF is calculated as:

where f is the average value of the pulling force in grams, and 81.1 is the mass of the slide, clamps and film.

For each sample, COF is measured at 5, 10, 25, 50, and 100 cm / min. A new piece of collagen film is used for each sample.

COF varies logarithmically with respect to speed, so the data are described using the following equation:

COF = a + SSP Ln (V),

where a is the most suitable COF at 1 cm / min, and SSP is the stick-slip parameter, showing how COF varies with speed. A higher SSP value indicates greater glide, less per sheet with stick-slip. SSP is measured for four tissue sheet samples for each species and the average value is fixed.

Hercules Size Test

A “Hercules Size Test” (HST) is a test that generally measures how long a fluid passes through a tissue sheet. The size test was performed in accordance with the TAPPI method T 530 PM-89, the size test for paper with ink resistance. Hercules size test data was collected on a Model HST test device using white and green calibration elements and a black disc provided by the manufacturer. 2% green Napthol Green N paint diluted with distilled water to 1% was used as a paint. All materials are available from Hercules, Inc., Wilmington, Delaware.

All samples were in conditions of 23 +/- 1 ° C and 50 +/- 2% relative humidity for at least 4 hours before testing. The test is sensitive to the temperature of the paint solution, so that the paint solution must also be balanced under controlled temperature conditions for at least 4 hours before the test.

Six (6) tissue sheets commercially available (18 layers for a 3-layer tissue product, 12 layers for a two-layer product, 6 layers for a single layer product, etc.) form a test specimen. Samples are cut to approximately 2.5 x 2.5 inches. The instrument is standardized using white and green calibration elements in the directions of the manufacturer. A sample (12 layers for a two-layer tissue product) is placed on the sample holder, so that the outer surface of the layers faces outward. The sample is then fixed in the sample holder. The sample holder is then placed in a retaining ring at the top of the visible body. Using a black disk, the instrument is calibrated to zero. The black disk is removed and 10 +/- 0.5 millimeters of the paint solution is distributed in the holding ring and the timer starts to work, while the black disk is returned to the sample. The test time in seconds (sec) is recorded from the instrument.

Extraction method for determining additional contents in a tissue

One way to measure the amount of additive composition in a tissue sample is to remove the additive composition with a suitable solvent. Any suitable solvent can be selected, and it can provide dissolution of at least most of the additives present in the tissue. One suitable solvent is xylene.

To begin with, a tissue sample containing the additive composition (3 g of tissue, at least for testing) was placed in an oven at 105 ° C overnight to remove all water. The dried napkin was then sealed in a metal can with a lid and allowed to cool in a desiccator containing a moisture absorber, calcium sulfate to prevent absorption of moisture from the air. After cooling the sample for 10 minutes, the weight of the wipes was measured on the balance with an accuracy of +/- 0.0001 g, and this weight was recorded (W ₁ ).

Extraction was carried out using a Soxhlet apparatus. The Soxhlet apparatus consists of a 250 ml round-bottomed glass flask connected to a Soxhlet extraction tube (Corning® no.3740-M, with a capacity of up to the top of the siphon 85 ml), and an Allhin condenser (Corning® no. 3840-MCO). The condenser was connected to a source of fresh cold water. The round bottom flask was heated from below using an electrically heated casing (Glas Col, Terre Haute, IN USA) controlled by a variable automatic transformer (Superior Electric Co., Bristol, CT USA).

To perform the extraction, a pre-weighed napkin containing the additive composition was placed in a 33 mm by 80 mm cellulose extraction cup (Whatman International Ltd, Maidstone, England). The beaker was then placed in a Soxhlet extraction tube and the tube was connected to a rounded bottom flask and a condenser. Inside the rounded bottom flask was 150 ml of xylene solvent. The heating jacket was activated and the flow of water through the condenser was started. The thermal control of the variable automatic transformer was controlled so that the Soxhlet tube was filled with xylene and cyclically returned to the flask with a rounded bottom every 15 minutes. Extraction was carried out over a total of 5 hours (approximately 20 cycles of xylene through a Soxhlet tube). Upon completion, the glass containing the tissue was removed from the Soxhlet tube and allowed to dry in the body. The wipe was then transferred to an oven at 150 ° C. and dried for 1 hour to remove excess xylene solvent. This furnace had air communication with the body. The dry wipe was then placed in an oven at 105 ° C. overnight. The next day, the napkin was removed, placed in a metal can with a lid and allowed to cool in a desiccator containing a moisture absorber, calcium sulfate for 10 minutes. The weight of the dry chilled extracted wipe was then measured on a balance with an accuracy of +/- 0.0001 g, and this weight was recorded (W ₂ ).

The percentage (%) of xylen extractive substances was calculated using the following uranium:

% xylene extractives = 100 × (W ₁ -W ₂ ) / W ₁ .

Since not all of the additive composition can be extracted in the selected solvent, it is necessary to create a calibration curve to determine the amount of the additive composition in an unknown sample. A calibration curve was developed by first applying a known amount of additive to the surface of a pre-weighed wipe (T ₁ ) using an airbrush. The additive composition was applied uniformly on a napkin and allowed to dry in an oven at a temperature of 105 ° C all night. The weight of the treated wipes was then measured (T ₂ ) and the weight% of the additive was calculated using the following equation:

% additive = 100 * (T ₂ -T ₁ ) / T ₁ .

Treated wipes with levels of additive compositions ranging from 0% to 13% were produced and tested using the Soxhlet extraction method described above. A linear regression of% xylene extractives (variable Y) to% addition (variable X) was used as a calibration curve.

Calibration curve:% xylen extractives = m (% additive) + b

Or:% additives = (% xylen extractive substances-b) / m,

where m = the slope of the equation in the linear regression equation;

b = line segment of the linear regression equation.

After creating a calibration curve, an additional composition on a tissue sample can be determined. The content of xylene extractives in the tissue sample was measured using the Soxhlet extraction method described above. % additives were then calculated using the linear regression equation:

% additives = (% xylen extractive substances-b) / m,

where m = the slope of the equation in the linear regression equation;

b = line segment of the linear regression equation.

At least two measurements were made on each tissue sample and the arithmetic mean was presented as the percentage of the additive.

Dispersion measurements - in a tank for dynamic movement

The dynamic displacement container used to dynamically destroy the samples consists of a plastic container measuring 14 inches wide, 18 inches deep and 12 inches high, made of 0.5 inch thick plexiglass with a tight-fitting lid. The tank is mounted on the platform, with one end attached to the hinge, and the other end attached to the reciprocating cam. The amplitude of the oscillating movement of the tank for dynamic movement is +/- 2 (range of 4 inches). The speed of dynamic action varies, but was set at a constant speed of 20 revolutions of the cam per minute or 40 dynamic movements per minute. A 2000 ml soaking solution of either “tap water” or “soft water” was added to the container for dynamic movement before testing. The tap water solution may contain about 112 ppm HCO ^- ₃ , 66 ppm Ca ²⁺ , 20 ppm Mg ²⁺ , 65 ppm Na ⁺ , 137 ppm Cl ^- , 100 ppm SO ^{2 -} ₄ with a total dissolved solids content of 500 ppm and a calculated water hardness of about 248 ppm equivalent CaCO ₃ . A soft water solution, on the other hand, contains about 6.7 ppm Ca ²⁺ , 3.3 ppm Mg ^2+, and 21.5 ppm Cl ^— with a total dissolved solids content of 31.5 ppm and a calculated water hardness of about 30 ppm CaCO ₃ equivalent. The sample was laid out and placed in a container for dynamic movements. The tank for dynamic movements began to work and the calculation of time began as soon as the sample was added to the solution for soaking. The destruction of the sample in the tank for dynamic movements was observed visually and the time required for destruction into pieces smaller than 1 square inch of the surface was recorded. At least three repetitions of the test samples were recorded and the average was calculated to obtain the recorded values. A sample that did not break into pieces with a size of less than about 1 square inch of surface for 24 hours in a particular soaking solution was considered non-dispersible in this soaking solution by this test method.

In this example, 14 tissue samples were made in accordance with the present invention and subjected to at least one of the tests described above, and the results were compared with various commercially available tissue products.

The first three samples made in accordance with the present invention (Sample No. 1, 2 and 3 in the table below) were made in accordance with the process described in Example 3 above.

Samples of tissue sheets 4-7, on the other hand, were made, in General, in accordance with the process shown in Fig.3. In order to adhesively attach the tissue to the creping surface, which in this embodiment is a Yankee dryer, an additional composition made in accordance with the present invention was sprayed onto the dryer before the dryer was contacted with the canvas. Two-layer or three-layer tissue products were produced. Samples were then subjected to various standardized tests.

First, softwood Kraft pulp (NSWK) was dispersed in the pulper for 30 minutes at a consistency of 4% and at 100 ° F. Then the NSWK pulp was transferred to the mass pool and subsequently liquefied to a consistency of about 3%. The NSWK pulp was then cleaned at 4.5 bhp / metric ton. The aforementioned softwood fibers were used as an inner strong layer in a three-layer tissue structure. The NSWK layer occupied approximately 34% of the final product weight.

Two kilograms of KYMENE® 6500 wet strength polymer, available from Hercules Incorporated, Wilmington, Delaware, USA, per metric ton of wood fiber was added to the composition in front of the headbox.

Aracruz ECF kraft pulp of eucalyptus hardwood (EHWK), available from Rio de Janeiro, RJ, Brazil, was dispersed in the pulper for 30 minutes at a consistency of 4% and at 120 ° F. Then the EHWK pulp was transferred to the mass pool and subsequently liquefied to a consistency of about 3%. Pulp EHWK represented two outer layers of a three-layer tissue structure. EHWK layers occupied approximately 66% of the final sheet weight.

Two kilograms of KYMENE® 6500 per metric ton of wood fiber was added to the composition in front of the headbox.

Pulp fibers from the mass pool were pumped into the headbox with a consistency of about 0.1%. The pulp fibers of each machine pool passed through separate manifolds in the headbox to create a three-layer tissue structure. Fibers were placed on felt material in the net portion of the molding apparatus in a manner similar to the process shown in FIG. 3.

A wet sheet with a consistency of about 10-20% was adhesively adhered to a Yankee dryer moving at about 2500 feet per minute (750 meters per minute) by means of a compression roll. The wet sheet consistency after clamping the press roll (consistency after the press roll or PPRC) was approximately 40%. The wet sheet was adhesively adhered to the Yankee dryer due to the additive composition that is applied to the surface of the dryer. Spray booms located downstream of the Yankee dryer have sprayed the additive composition described in the present invention onto the surface of the dryer with an addition level of 100 to 600 mg / m ² .

To prevent contamination of the felt material with the additive composition and to maintain the desired properties of the sheet, a protective agent was placed between the spray boom and the press roll.

The sheet was dried to a consistency of about 95% -98% when it was transported on a Yankee dryer and to a creping knife. The creping knife then removes the tissue sheet and part of the additive composition from the Yankee dryer. The creped main tissue sheet was then wound around a core moving at about 1970 feet per minute (600 meters per minute) to form soft rolls for conversion. The resulting main tissue sheet had a base weight of 14.2 g / m ² when air dried. Two or three soft rolls of creped napkins were then rewound and folded together, so that both creped sides were on the outer sides of a two-layer or three-layer structure. Mechanical compression at the edges of the structure holds the layers together. The laminated sheet was then cut at the edges to a standard width of approximately 8.5 inches and folded. Tissue samples were placed under certain conditions and tested.

The additive composition, which was applied to Samples No. 4-7 and tested, was as follows.

Polymer (weight ratio in parentheses) Dispersant Dispersant, conc. (the weight.%) AFFINITY ™ EG8200 / PRIMACOR ™ 5986i (60/40) PRIMACOR ™ 5986 40.0

The particle size of the polymer (μm) Poly dispersion Solids (wt.%) pH Viscosity (cP) Pace. ° C Rpm Spindle 0.71 2.12 40,0 11.3 448 22.1 fifty RV3

The DOWICIL ™ 200 antimicrobial product, which is a preservative supplemented with 96% cis 1- (3-chlorallyl) -3,5,7-triaz-1-azoniaadamantane chloride (also known as Quaternium-15), obtained from The Dow Chemical Company is also present in each of the additional compositions.

The percentage of solids in the solution for various additive compositions was varied to provide 100 to 600 mg / m ² spray coating on a Yankee dryer. A change in the solids content of the solution also changes the amount of solids included in the base web. For example, with a spray coating of 100 mg / m ² on a Yankee dryer, it was found that about 1% of the solids of the additive composition are included in the tissue web. With a spray coating of 200 mg / m ² on a Yankee dryer, it was found that about 2% of the solids of the additive composition are included in the tissue. With a spray coating of 400 mg / m ² on a Yankee dryer, it was found that about 4% of the solids of the additive composition is included in the tissue web.

Samples No. 8-13, on the other hand, were produced in accordance with the process described in Example 2 above.

Sample wipes No. 14, on the other hand, contained a two-layer product. Napkin sample No. 14 was performed similarly to the process described in Example 3. Napkin cloth was essentially dried before attaching to the dryer drum using an additive composition.

Before testing, all samples were kept under certain conditions in accordance with the TAPPI standard. More specifically, the samples were placed in an atmosphere with 50% relative humidity and 72 ° F. for at least four hours.

The following results were obtained.

As shown above, samples made in accordance with the present invention have a good absorption rate, as shown by the Hercules size test. More specifically, samples made in accordance with the present invention had an HST of less than 60 seconds, such as less than 30 seconds, such as less than 20 seconds, such as less than 10 seconds. In fact, many samples had an HST of less than about 2 seconds.

In addition to high water absorbency, paper towel samples made in accordance with the present invention, even containing the additive composition, had good dispersion properties. For example, as shown, the samples had a dispersion of less than about 2 minutes, such as less than about 1-1 / 2 minutes, such as less than about 1 minute.

As shown in the table above, samples made in accordance with the present invention had excellent adhesion-slipping properties. The stick-slip data is also shown in FIG. 28. As shown, samples made in accordance with the present invention had adhesion-slipping from about 0.007 to about 0.1. More specifically, samples made in accordance with the present invention had adhesion-slippage greater than about -0.006, such as more than about 0. All comparative examples, on the other hand, had lower adhesion-slippage values.

Example 5

Tissue samples in accordance with the present description were made similar to the process described in Example 4 above. In this example, the additive composition was applied to the first sample in a relatively large amount, and to the second sample in a relatively small amount. More specific. Sample No. 1 contained an additive composition in an amount of 23.8 wt.%. Sample No. 1 was performed similarly to the production method of Sample No. 1 in the above Example No. 4. Sample No. 2, on the other hand, contained an additive composition in an amount of about 1.2 wt.%. Sample No. 2 was performed, in General, in the same manner as Example No. 4 in the above Example No. 4.

After manufacturing the samples, one surface of each sample was photographed using a scanning electron microscope.

A first sample containing the additive composition in an amount of 23.8% by weight is shown in FIGS. 29 and 30. As shown, in this sample the additive composition forms an intermittent film on the surface of the product.

Fig.31-34, on the other hand, are photographs of a sample containing the additive composition in an amount of about 1.2 wt.%. As shown, at relatively low amounts, the additive composition does not form an interconnected network. Instead, the additive composition is present on the surface of the product in separate and divided areas. Even with relatively low amounts, however, the tissue product still has a lotion feeling and softness.

Example 6

In this example, various compositions were printed onto a non-creped web-dried web (UCTAD) in accordance with a pattern and creped from a creping drum. The compositions were used to adhere the main web to the drum. Samples were then tested for blocking, which refers to the tendency of two adjacent sheets to stick together.

More specifically, the blocking test was carried out in this example as follows.

Blocking test

1. Get samples of the main sheet to be tested. Samples were cut so as to obtain a width of 3 inches and a length of 6 to 7 inches. The width of the samples is the transverse machine direction, while the length is the machine direction of the main sheet.

2. Take two identical samples and place them on top of each other. When testing creped tissue sheets, the non-creped side of each sheet is facing up. Thus, the non-creped side of the bottom sheet is positioned to contact the creped side of the top sheet.

3. Repeat the above step 2 until five samples or stacks are made.

4. Place the LEXAN PLEXIGLAS piece on a flat surface. LEXAN PLEXIGLAS has a thickness of _^1/4 inch. A piece of printing and copy paper, twenty pounds, 8.5 inches by 11 inches and a brightness of 98 was placed on top of the LEXAN PLEXIGLAS.

5. Place a stack of samples on top of each other on the PLEXIGLAS. Each stacked sample was separated by carbon paper as shown in FIG. 38.

6. A piece of printing and copy paper, 12 pounds, 8.5 inches by 11 inches with a brightness of 98 was then placed on top of the sample and the resulting stack was covered on top with another piece of LEXAN PLEXIGLAS, as also shown in Fig. 38.

7. A weight of 16 pounds was placed on a piece of PLEXIGLAS, as also shown in FIG. 38. The whole structure was then placed in a holding chamber with a controlled temperature of 40 ° C and a relative humidity of 75% for five days.

8. After aging, each sample was then removed from the structure shown in FIG. 38. Each sample was then placed in a tensile testing device equipped with a computerized data acquisition system that can calculate the average peeling strength in gram-force. The tensile tester is a Sintech Tensile Tester with TESTWORKS software. TESTWORKS software uses a 640-W peeling method in which the cams are set to one inch.

9. Take the first sample and gently begin to separate the two tissue sheets along the upper edge. Place one sheet of specimen on the lower cam, and another sheet of specimen on the upper cam of the tensile testing device. When using creped tissue sheets, the creped side of the specimen is visible and faces outward.

10. Begin a test to measure blocking force. More specifically, the tensile tester peels two sheets apart. Peeling is carried out along the length (machine direction) of the sample. The test is repeated for all five samples obtained, and the blocking force is measured and averaged for five samples.

In this example, uncreated dried through-flow main webs were formed in a process similar to the process shown in FIG. 2. The base sheets had a base weight of 42.7 g / m2 to 44.5 g / m2. The main sheet was made from 100% kraft pulp of soft northern wood species.

As shown above, after forming, the base sheets were then subjected to a creping process with printing. The creping process with printing is generally shown in FIG. The sheet was fed into an engraving line, where the creping composition was applied to the surface of the sheet by printing in a manner similar to the process described in Example 2 above.

In the first set of samples, a creping adhesive was applied to the base sheet. An additive composition made in accordance with the present invention was then added in varying amounts to the creping adhesive. Finally, samples were made containing an additive composition made in accordance with the present invention.

The creping adhesive used was an AIRFLEX 426 binder obtained from Air Products, Inc., Allentown, PA. AIRFLEX 426 is a plate emulsion of a cross-linked terpolymer of carboxylated vinyl acetate and ethylene.

An additional composition made in accordance with the present invention was as follows.

Polymer (weight ratio in parentheses) Dispersant Dispersant, conc. (the weight.%) AFFINITY ™ EG8200 / PRIMACOR ™ 5986i (60/40) PRIMACOR ™ 5986 40.0

The particle size of the polymer (μm) Poly dispersion Solids (wt.%) pH Viscosity (cP) Pace. ° C Rpm Spindle 0.71 2.12 40,0 11.3 448 22.1 fifty RV3

The following samples were obtained containing a creping adhesive and an additive composition in the following percentages.

Sample No. % Crepe Adhesive % Additive composition one one hundred 0 2 98 2 3 90 10 four 75 25 5 0 one hundred

Blocking the sheet was tested for each of the above samples in accordance with the process described above. The blocking results are shown in Fig. 39. Samples were also tested for GMT, GMTEA, GMM / GMT and for transverse dry / wet tearing. The following results were obtained.

Sample No. GMT (gram power) GMTEA (J / m ² ) GMMod / GMT % W / D in the transverse direction one 1720 36.8 3.71 55 Raw 1055 21,4 4.02 34 2 1061 22.3 3.83 33 3 1224 23.8 4.09 34 four 1416 25.8 4.84 thirty 5 2783 41.5 6.54 45

As shown in FIG. 39, blocking decreases dramatically when the amount of additive composition in the creping composition increases. Indeed, blocking of the sheet is not substantially detected in Sample No. 5, which does not contain any creping adhesive.

As shown in the table above, the additive composition in accordance with the present invention also significantly increases the geometric mean tensile strength of the base sheet compared to a substantially identical but untreated sample. For example, the geometric mean tensile strength is more than double that of untreated Sample No. 5, which contains only an additive composition.

In this regard, based on various factors, the geometric mean tensile strength of the base sheet processed in accordance with the present invention can increase by more than 10%, more than 25%, more than 50%, more than 75% more than 100%, more than 125%, more than 150%, more than 175% and even more than 200% compared with a substantially identical untreated sample

As also shown in the above table, various other properties of the base sheet were improved when the base sheet was treated with an additive composition made in accordance with the present invention, compared with the untreated sample.

In the following set of samples, various other additives were combined with a creping adhesive. More specifically, the creping adhesive mixture in addition to the AIRFLEX 426 binder contained KYMENE 6500, available from Hercules, Incorporated. KYMENE 6500 is a wet strength agent. The creping adhesive mixture also contained HERCOBOND, available from Hercules, Incorporated, PROTOCOL CB2008 anti-foam agent, available from Hercules, Incorporated, and sodium hydroxide.

Chemical substance % Songs AIRFLEX 426 43.3 PROTOCOL CB2008 0.2 Water 32 KYMENE 6500 13.6 HERCOBOND 1366 9.1 NAOH (10%) 1.8

The following samples were prepared containing combinations of a mixture of creping adhesive and an additive composition made in accordance with the present invention.

Sample No. % Crepe Adhesive Mixtures % Additive composition 6 one hundred 0 7 97.5 2.5 8 95 5 9 25 75

The above samples provide the following results.

Sample No. GMT (gram power) GMTEA (J / m ² ) GMMod / GMT % W / D in the transverse direction 6 1720 36.8 3.71 55 7 1511 30,2 4.04 60 8 1478 31 4.16 53 9 2343 37.9 9.26 43

The blocking results are shown in FIG. As shown, blocking is significantly reduced than large amounts of the additive composition are contained in the creping adhesive.

As a result of these tests, it was noted that the creping mixture containing KYMENE 6500 sought to precipitate the additive composition from solution. As a result, additional samples were made in which the creping adhesive mixture did not contain the KYMENE 6500 product. More specifically, the following samples were produced.

Sample No. % Crepe Adhesive Mixtures % Additive composition 10 one hundred 0 eleven 98 2 12 90 10 13 75 25 fourteen 25 75 fifteen 0 one hundred

The above samples provided the following results.

Sample No. GMT (gram power) GMTEA (J / m ² ) GMMod / GMT % W / D in the transverse direction 10 2163 43.7 4.08 31 eleven 2197 43,4 3.95 thirty 12 1956 37 4.28 33 13 1642 31.5 4.88 32 fourteen 2133 32.8 7.93 44 fifteen 2783 41.5 6.54 45

The blocking results are shown in FIG. 4. As shown, blocking decreases as the amount of additive composition present increases.

As shown above, sheet blocking can be less than 15 gs, such as less than 10 gs and even less than 5 gs, when the creping adhesive contains an additive composition made in accordance with the present invention.

Example 7

In this example, tissue sheets made in accordance with the present description were compared with untreated sheets and various commercially available products. More specifically, the samples were subjected to a hairiness test, in which the amount of fluff formed by the samples was measured.

Hair test

The value of “hairiness test” is a test that measures the resistance of the tissue material to abrasion when the material is exposed to an abrasion test device with horizontal reciprocating surfaces. More specifically, FIG. 42 is a schematic diagram of test equipment that can be used to abrade a sheet in accordance with a hairiness test. As shown, a device 201 having a mandrel 203 receives a tissue sheet 202. A sliding magnetic clip 208 with guide pins (not shown) is located opposite the stationary magnetic clip 209, also having guide pins 210 and 211. A cycle speed control device 207 and a control device are provided. start / stop 205. Counter 206 shows samples or cycles. The mandrel used for abrasion consists of a 0.5-inch diameter stainless steel rod with an abrasive section containing a coating of 18-22 micron diamond particles (deposited by SuperAbrasives, Inc., 28047 Grand Oaks Conn., Wixom, Mich. 48393) extending 4.25 inches in length around the entire perimeter of the shaft. The mandrel is mounted perpendicular to the surface of the device, so that the abrasive portion of the mandrel extends from the front surface of the device. On each side of the mandrel are guide pins 210 and 211, which are used to interact with the sliding magnetic clamp 208 and the stationary magnetic clamp 209, respectively. The sliding magnetic clamp and the stationary magnetic clamp are spaced about 4 inches apart and are centered around the mandrel. The sliding magnetic clamp and the stationary magnetic clamp are designed to slide freely in the vertical direction.

Samples were cut using a paper cutter and precision cutter into 3 inch wide and 7 inch long samples. Each specimen should be cut in such a way that when it is placed in the device for testing for hairiness, the mandrel does not have an abrasive effect on any perforations (if any). Only the napkin side facing outward from the roll is tested. For tissue sheets that are treated with the additive composition on only one side, the side on which the additive composition is applied is tested. For tissue samples, the machine direction (MN) corresponds to a longer size. Each test strip weighs about 0.1 mg. The sample 202 is placed opposite the guide pins (not on them) and held in place by a sliding magnetic clip 208. The sample is wrapped on a mandrel and placed opposite the guide pins and use a stationary magnetic clip 209. When the sample is in place, the sliding magnetic clip is released to pull the sample tight and exactly.

Mandrel 203 then moves back and forth along an arcuate path with a radius of 4.968 inches and a length of 2.68 inches from the test strip for 40 cycles (each cycle consists of back and forth moves) at a speed of about 80 cycles per minute, while removing loose fibers from surface of the canvas. A sliding magnetic clamp and a stationary magnetic clamp are then removed from the sample. All liberated residues are removed by holding one corner of the sample with your fingertips and blowing both sides of the sample with compressed air (approximately 5-10 psi). The sample is weighed about 0.1 mg and weight loss is calculated. Ten typical test samples per napkin are tested, and the average weight loss, in milligrams, represents the value of the hairiness test for the sample. Between the test passes, compressed air is used to blow out residues and fluff from the mandrel and the test area.

In this example, tissue sample samples were made in accordance with the process shown in FIG. 3. In order to adhesively attach the tissue to the creping surface, which in this embodiment is a Yankee dryer, an additional composition made in accordance with the present invention was sprayed onto the dryer before the dryer was contacted with the canvas. Bilayer tissue products were obtained. Samples were then subjected to various standardized tests.

First, softwood Kraft pulp (NSWK) was dispersed in the pulper for 30 minutes at a consistency of 4% and at 100 ° F. Then the NSWK pulp was transferred to the mass pool and subsequently liquefied to a consistency of about 3%. The NSWK pulp was then cleaned at 4.5 hp. days / metric ton. The aforementioned softwood fibers were used as an inner strong layer in a three-layer tissue structure. The NSWK layer occupied approximately 34% of the final product weight.

Two kilograms of KYMENE® 6500 wet strength polymer, available from Hercules Incorporated, Wilmington, Delaware, USA, per metric ton of wood fiber was added to the composition in front of the headbox.

Aracruz ECF kraft pulp of eucalyptus hardwood (EHWK), available from Rio de Janeiro, RJ, Brazil, was dispersed in the pulper for 30 minutes at a consistency of 4% and at 120 ° F. Then the EHWK pulp was transferred to the mass pool and subsequently liquefied to a consistency of about 3%. Pulp EHWK represented two outer layers of a three-layer tissue structure. EHWK layers occupied approximately 66% of the final sheet weight.

Two kilograms of KYMENE® 6500 per metric ton of wood fiber was added to the composition in front of the headbox.

Pulp fibers from the mass pool were pumped into the headbox with a consistency of about 0.1%. The pulp fibers of each machine pool passed through separate manifolds in the headbox to create a three-layer tissue structure. Fibers were placed on felt material in the net portion of the molding apparatus, and then fed into a Yankee dryer.

A wet sheet with a consistency of about 10-20% was adhesively adhered to a Yankee dryer moving at about 2500 feet per minute (750 meters per minute) through a clamp using a press roll. The wet sheet consistency after clamping the press roll (consistency after the press roll or PPRC) was approximately 40%. The wet sheet was adhesively adhered to the Yankee dryer due to the additive composition that is applied to the surface of the dryer. Spray booms located below the Yankee dryer have sprayed the additive composition described in the present invention onto the surface of the dryer with an addition level of 100 to 600 mg / m ² .

To prevent contamination of the felt material with the additive composition and to maintain the desired properties of the sheet, a protective agent was placed between the spray boom and the press roll.

The sheet was dried to a consistency of about 95% - 98% when it was transported on a Yankee dryer and to a creping knife. The creping knife then removes the tissue sheet and part of the additive composition from the Yankee dryer. The creped main tissue sheet was then wound around a core moving at about 1970 feet per minute (600 meters per minute) to form soft rolls for conversion. The two soft rolls of creped napkins were then rewound and folded together so that both creped sides were on the outer sides of the two-layer structure. Mechanical compression at the edges of the structure holds the layers together. The laminated sheet was then cut at the edges to a standard width of approximately 8.5 inches and folded. Tissue samples were placed under certain conditions and tested.

Polymer (weight ratio in parentheses) Dispersant Dispersant, conc. (the weight.%) AFFINITY ™ EG8200 / PRIMACOR ™ 5986i (60/40) PRIMACOR ™ 5986 40.0

The particle size of the polymer (μm) Poly dispersion Solids (wt.%) pH Viscosity (cP) Pace. ° C Rpm Spindle 0.71 2.12 40,0 11.3 448 22.1 fifty RV3

The DOWICIL ™ 200 antimicrobial product, which is a preservative supplemented with 96% cis 1- (3-chlorallyl) -3,5,7-triaz-1-azoniaadamantane chloride (also known as Quaternium-15), obtained from The Dow Chemical Company is also present in each of the additional compositions.

The percentage of solids in solution for various additive compositions varied between 200 mg / m ² and 400 mg / m ^{2 of the} spray coating on a Yankee dryer. A change in the solids content of the solution also changes the amount of solids included in the base web. With a 200 mg / m ² spray coating on a Yankee dryer, the additive composition is included in the tissue web at about 2% by weight. With a spray coating of 400 mg / m ² on a Yankee dryer, it was found that the additive composition was included in the tissue web at about 4% by weight.

For comparison, a two-layer sample was also produced in accordance with the same process. Instead of using the additive composition of the present invention, however, a standard creping adhesive was applied to a Yankee dryer. Thus, the samples, which were then tested, included sample No. 1 containing the additive composition in an amount of 2 wt.%. Sample No. 2 containing the additive composition in an amount of 4 wt.%, And a Control sample not containing the additive composition. In addition, commercially available facial wipes were also tested. More specifically, KLEENEX wipes, KLEENEX ULTRASOFT wipes and PUFFS wipes, which, on the other hand, contain three layers and are treated with silicone.

Before testing, all samples were kept under conditions consistent with TAPPI standards. More specifically, the samples were placed in an atmosphere of 50% relative humidity and 72 ° F. for at least four hours.

The following results were obtained.

As shown above, the samples made in accordance with the present invention, had a significantly better value test for hairiness than other samples.

These and other modifications and changes of the present invention can be practiced by those skilled in the art without departing from the scope and spirit of the present invention, which are set forth in more detail in the attached claims. In addition, it should be understood that objects of various embodiments may be interchangeable both in whole and in part. In addition, it will be understood by those skilled in the art that the above description is exemplary only and is not intended to limit the invention described in the appended claims.

Claims (20)

1. A tissue product containing:
a tissue sheet having a first side and a second side, wherein the tissue sheet contains cellulosic fibers in an amount of at least 50% by weight; an additive composition present on at least a first side of the tissue sheet, wherein the additive composition comprises a polymer; and the product has a volume above about 3 cm ³ / g, has a hairiness test value of less than about 3 mg, and the first side of the tissue sheet has a stick-slip value of above about 0.01. 2. The tissue product of claim 1, wherein the product has a hairiness test value of less than about 2.5 mg. 3. The tissue product of claim 1, wherein the product has a hairiness test value of less than about 2 mg. 4. The tissue product according to claim 1, in which the first side of the tissue sheet has a stick-slip value of from about 0.006 to 0.7. 5. The tissue product of claim 1, wherein the product has a geometric mean tensile strength of at least 600 g / 3 inches and a wet / dry extensibility of at least about 25%. 6. The tissue product of claim 1, wherein the additive composition comprises a non-fibrous olefin polymer, a copolymer of ethylene and a carboxylic acid, or mixtures thereof. 7. The tissue product of claim 6, wherein the additive composition comprises a non-fibrous olefin polymer, the olefin polymer comprising an alpha-olefin interpolymer of ethylene and at least one comonomer selected from the group consisting of C ₄ -C ₂₀ linear, branched or cyclic diene, vinyl acetate and a compound represented by the formula H ₂ C = CHR, wherein R is C ₁ -C ₂₀ linear, branched or cyclic alkyl group or a C ₆ -C ₂₀ aryl group or an alpha-olefin polymer comprises a copolymer etc. Pilėnai with at least one comonomer selected from the group consisting of ethylene, C ₄ -C ₂₀ linear, branched or cyclic diene, and a compound represented by the formula H ₂ C = CHR, wherein R is C ₁ -C ₂₀ linear, a branched or cyclic alkyl group or a C ₆ -C ₂₀ aryl group. 8. The tissue product of claim 6, wherein the additive composition comprises a mixture of an olefin polymer and a copolymer of ethylene and a carboxylic acid, and wherein the olefin polymer contains an ethylene-alkene interpolymer, the additive composition further comprising a carboxylic acid. 9. The tissue product of claim 8, wherein the dispersing agent comprises a carboxylic acid, a carboxylic acid salt, a carboxylic acid ester or a carboxylic acid ester salt. 10. A tissue product according to any one of claims 1 to 7, 8 or 9, wherein the tissue sheet comprises at least one tissue web that forms the first side, and wherein the additive composition is applied to the first side of the tissue web, and a tissue web was creped after the additive composition was applied. 11. Tissue product according to any one of claims 1 to 7, 8 or 9, in which the additive composition was first applied to the creping surface, and then the first side of the tissue was contacted with the creping surface to apply the additive composition to the first side of the fabric before creping the tissue canvases. 12. The tissue product of claim 10, wherein the additive composition was applied to the first side of the tissue web in accordance with the pattern before creping. 13. A tissue product according to any one of claims 1 to 7, 8 or 9, wherein the tissue sheet contains a substance for imparting temporary wet strength. 14. A tissue product according to any one of claims 1 to 7, 8, or 9, wherein the tissue sheet contains a substance to impart a constant wet strength. 15. Tissue product according to any one of claims 1 to 7, 8 or 9, in which the tissue sheet consists of only one layer of tissue paper containing cellulose fibers. 16. Napkin product according to any one of claims 1 to 7, 8 or 9, in which the tissue sheet contains many layers. 17. Napkin product according to any one of claims 1 to 7, 8 or 9, in which the tissue product contains many individual tissue sheets, which are in a folded stack of configuration. 18. A tissue product according to any one of claims 1 to 7, 8 or 9, wherein the tissue product is a spirally wound product. 19. Tissue product according to any one of claims 1 to 7, 8 or 9, in which the product is essentially dry. 20. A tissue product according to any one of claims 1 to 7, 8, or 9, wherein the presence of the additive composition increases the geometric mean tensile strength of the tissue sheet by at least 10% compared to a substantially identical untreated tissue sheet.

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