MXPA06007590A - Nonwoven webs having reduced lint and slough - Google Patents

Abstract

Nonwoven webs having reduced levels of lint and slough are disclosed. In accordance with the present invention, the nonwoven webs are treated on at least one surface with a small amount of a polymeric component. The polymeric component may be present, for instance, in the form of meltblown fibers. The meltblown fibers are made from a polymer that is compatible with the nonwoven web. By adding relatively small amounts of meltblown fibers to at least one side of the nonwoven material, lint and slough levels have been found to be significantly reduced. The nonwoven web may be any web containing pulp fibers, such as a tissue web or a coform web.

Description

NON-WOVEN FABRICS THAT HAVE REDUCED LUSH AND DETACHMENT BACKGROUND OF THE INVENTION Pulp fibers, such as softwood fibers and hardwood fibers, are incorporated into numerous non-woven materials. Nonwoven materials, in turn, are used in the majority of a variety without limit of applications For example, pulp fibers. they are used to form tissue products, including facial tissues, bath tissues, paper towels, industrial cleansing cloths, and the like. The pulp fibers are also incorporated into the non-woven composite materials which may contain pulp fibers in combination with polymer fibers. The nonwoven composite materials can be used, for example, to make wet wipes, tablecloths, surgical covers, bandages, and absorbent structures for incorporation into disposable absorbent garments such as diapers, feminine care products, and incontinence products. of adults.

The pulp fibers may be constructed to have high absorbency properties and may have a soft feel to the skin when incorporated into the above non-woven materials. In addition, pulp fibers are relatively inexpensive to obtain, which allows the production of relatively inexpensive products, which can be disposed after a single use.

Nonwovens that incorporate pulp fibers are designed to include several important properties. For example, in some applications, non-woven materials should have good volume, a smooth feel, and should have good strength. Unfortunately, however, when steps are taken to increase a property of the material, other characteristics of the material are often adversely affected.

For example, in many applications, the pulp fibers are treated with chemical binder which are designed to reduce the fiber bond between the pulp fibers. Reducing the fiber bond can increase the softness of the material. Chemical debonders, however, can also sometimes adversely affect the strength of the non-woven material, especially when the material compresses a tissue product.

For example, the inclusion of chemical binder in non-woven materials can result in loose bonded fibers extending from the surface of the non-woven material. During use, when non-woven materials are subjected to cutting forces, the loose bonded fibers may be released from the material and may remain suspended in the air or may result in detachment, which is when the Bales or bales of fibers are transferred onto an adjacent surface, such as the user's skin or clothes.

Detachment or lint can be particularly problematic in creped tissue, where the disruption of the surface caused by creping can result in released fibers that can be released from the sheet like lint during use. Layered tissues, with a high content of hardwood in an outer layer, can also undergo severe lint problems.

Thus, in the lint and detachment there is generally a problem faced by the manufacturers of cleaning cloth products containing pulp fibers, such as tissue products and wet pre-saturated cleaning cloths. Efforts to reduce detachment and lint without a noticeable loss of volume and softness have not been completely successful. Therefore, there is currently a need for a method for reducing lint and detachment in non-woven materials containing pulp fibers.

DEFINITIONS As used herein, the term "meltblown fibers" means the fibers formed by the extrusion of a molten thermoplastic material through a plurality of fibers. thin and usually circular capillary matrix vessels with strands or filaments fused into gas jets heated at high velocity (e.g., air) and converging that attenuate the filaments of molten thermoplastic material to reduce its diameter, which can be to a micro fiber diameter. After this, the meltblown fibers are carried by the high speed gas jet and are deposited on a collecting surface to form a randomly dispersed meltblown fabric. Such process is described for example, in the patent of the United States of America number 3,849,241 granted to Butin and others.

As used herein, "spunbond fibers" refer to small diameter fibers that are formed by extruding a molten thermoplastic material as filaments through a plurality of fine spinner capillaries having a circular configuration or otherwise, with the diameter of the extruded filaments being rapidly reduced as, for example, in U.S. Patent No. 4,340,563 issued to Appel et al., and U.S. Patent No. 3,692,618 issued to Dorschner and others, which are each incorporated here by reference in its entirety to it.

As used herein, the term "coform" means a nonwoven composite material of a matrix material formed by air comprising meltblown fibers polymeric thermoplastics such as, for example, micro fibers having an average fiber diameter of less than about 10 microns, and a multiplicity of individualized absorbent fibers such as, for example, wood pulp fibers arranged throughout the matrix the polymer micro fibers and which hook at least some of the micro fibers to space the micro fibers apart from each other. The absorbent fibers are interconnected by and held captive within the matrix of the micro fibers by mechanical entanglement of the micro fibers with the absorbent fibers, the mechanical entanglement and the interconnection of the micro-fibers and the absorbent fibers alone form an integrated fibrous structure coherent These materials are prepared in accordance with the descriptions of the patents of the United States of America numbers 4,100,324 granted to Anderson et al .; 5,508,102 granted to Georger and others; U.S. Patent No. 5,284,703 issued to Everhart et al .; U.S. Patent No. 5,350,624 issued to Georger et al .; and U.S. Patent No. 5,385,775 issued to Wright, each of which is incorporated by reference in its entirety.

As used herein, the term "micro fibers" means fibers of small diameter that have an average diameter of no more than about 100 microns, for example, having a diameter from about 0.5 microns to about 50 microns, or more particularly, the micro fibers also they can have an average diameter from around 4 microns to around 40 microns.

As used herein, the term "autogenous bond" means the bond provided by the fusion and / or self-adhesion of fibers and / or filaments without an applied bonding agent or external adhesive. The autogenous bond can be provided by the contact between fibers and / or filaments while at least a part of the fibers and / or the filaments are semi-fused or sticky. The autogenous bond can also be provided by mixing a binder resin with thermoplastic polymers used to form fibers and / or filaments. The fibers and / or filaments formed from such a mixture can be adapted to self-bond with or without the application of pressure and / or heat. Solvents can also be used to cause melting of the fibers or filaments that remain after the solvent is removed.

As used herein, the terms "stretch-bonded laminate" or "composite elastic material" refer to a fabric material having at least one non-woven fabric layer being elastic and at least one layer of the non-woven fabric being non-woven. elastic, for example, a foldable layer. The layers of elastic non-woven fabric are bonded or bonded in at least two locations to the non-elastic nonwoven fabric layers. Preferably, the joints are in points or areas intermittent bonding while the strata of the nonwoven fabric are in a juxtaposed configuration and while the nonwoven fabric strata have a tension force applied thereto in order to bring the elastic nonwoven fabric to a stretched condition. With the removal of the tension force after joining the tissue layers, a stratum of the elastic non-woven fabric will attempt to recover to its unstretched condition and will therefore fold the non-elastic non-woven fabric stratum between the points or joining areas of the two strata. The composite material is elastic in the direction of stretching of the elastic layer during bonding of the layers and can be stretched until the folds of the non-elastic non-woven fabric or film have been removed. A laminate joined with stretch can include more than two layers. For example, the elastic nonwoven fabric or film may have a layer of non-elastic non-woven fabric bonded to both sides while in a stretched condition such that a three-layer non-woven fabric composite is formed having the structure of the non-elastic folded non-woven fabric or film, fabric or elastic non-woven film, and non-elastic folded non-woven fabric or film. However other combinations of non-elastic and elastic strata can also be used. Such elastic composite materials are described, for example, by U.S. Patent No. 4,720,415 issued to Vander Wielen et al., And the United States of America patent. number 5,385,775 granted to Wright, which are incorporated herein by reference.

SYNTHESIS OF THE INVENTION In general, the present invention is directed to a process for producing non-woven materials having reduced lint and detachment. The present invention is also directed to the materials produced by the process. The non-woven materials contain pulp fibers and in accordance with the present invention, include a "plated" meltblown applied to at least one side of the material that has been found to greatly reduce lint and peel without substantially affecting the other properties of the material .

Nonwoven materials made in accordance with the present invention can be used in numerous applications. For example, the nonwoven materials may comprise tissue products, such as facial tissue, bath tissue, paper towels, industrial cleaning cloths, and the like. In this embodiment, the nonwoven material comprises mainly pulp fibers. In an alternative embodiment of the present invention, the non-woven material is made of a composite fibrous fabric containing pulp fibers in combination with polymeric fibers. These composite materials can be used in several applications. By For example, the materials can be used to build previously saturated wet cleaning cloths. In addition to cleaning cloth products, the non-woven materials of the present invention can also be used in other applications, such as in the construction of disposable absorbent products, such as diapers, feminine hygiene products, adult incontinence products, bandages, medical covers, and the like.

In a particular embodiment, the present invention is directed to a non-woven fabric comprising pulp fibers. The nonwoven fabric has a first side and a second and opposite side. The melt blown fibers are applied to the first side of the fabric in a manner such as to reduce lint and detachment. The meltblown fibers can be, for example, distributed over the surface of the first side of the non-woven fabric. Melt-blown fibers have been found to reduce lint and detachment when placed on non-woven fabric at extremely low levels, such as less than about 8 grams per square meter (gsm). In other embodiments, for example, melt blown fibers may be present on the fabric in an amount of less than about 6 grams per square meter (gsm), in an amount of less than about 4 grams per square meter, in a amount of less than around 2 grams per square meter, and even in amounts of less than about 1 gram per square meter for some applications.

In a particular embodiment, the non-woven fabric treated with the meltblown fibers comprises a tissue of tissue. The tissue tissue can be formed by air or formed in accordance with a wet-laid process. For example, the tissue of the tissue can be an air-dried fabric without creping that has a "side to the fabric" and an "air side". As used herein, the fabric side of a non-creped continuous air-dried fabric is the side of the fabric that rests on a continuously dried fabric during a continuous drying process. The air side, on the other hand, is the opposite side of the fabric when the fabric is transported through a continuous air dryer. When air-dried fabrics are processed continuously without creping, the melt-blown fibers can be applied on the air side of the fabric, which typically exhibits higher levels of lint and peel. It should be understood, however, that meltblown fibers can also be applied to both sides of the fabric.

When tissue tissues are processed in accordance with the present invention, tissue tissues can be made primarily from pulp fibers, such as softwood fibers and hardwood fibers. In one embodiment, tissue tissue is made from a stratified fiber supply that it includes a first outer layer, a second outer layer, and a middle layer placed between the outer layers. The middle layer may contain, for example, hardwood fibers while the outer layers may contain softwood fibers or vice versa.

The meltblown fibers applied to the tissue of tissue may have a diameter of less than about 10 microns, such as less than about 5 microns. The fibers may comprise continuous filaments. The melt blown fibers can be made of various polymeric materials, such as styrene-butadiene copolymers, polyvinyl acetate homopolymers, ethylene vinyl acetate copolymers, acrylic vinyl acetate copolymers, ethylene vinyl chloride copolymers, vinyl acetate-vinyl chloride terpolymers ethylene, polyvinyl chloride acrylic polymers, acrylic polymers, nitrile polymers, and waxes such as paraffin wax. The meltblown fibers can be made of thermo-fixed polymers, photo-cured polymers, and thermoplastic polymers. In a particular embodiment, the melt blown fibers are made of ethylene vinyl alcohol or an ethylene vinyl acetate copolymer.

In one embodiment, the meltblown fibers comprise a polymer with a plurality of hydrophilic groups such as carboxylic acid groups or salts thereof. the same, or of hydroxyl groups, which, in some cases, can help to provide good adhesion with cellulose even when the cellulose is wet. Such adhesives may comprise polyvinyl alcohols or ethylene vinyl acetate (EVA), and may include, by way of example, hot melt EVA HYSOL® from Henkel Loctite Corporation (of Rocky Hill, Connecticut), including 232 EVA HYSOL®, 236 EVA HYSOL®, 1942 EVA HYSOL®, 0420 EVA HYSOL®, SP AYPAC®, 0437 EVA HYSOL® SPARYPAC®, cold-cast EVA HYSOL®, QuikPac EVA HYSOL®, SuperPac EVA HYSOL®, and WaxPac EVA HYSOL®. Ethylene vinyl acetate (EVA) based adhesives can be modified through the adhesion of glutinizers and other conditioners, such as Wingtack 86 glutinating resin, manufactured by GoodYear Corporation, (of Akron, Ohio).

In another embodiment, the meltblown fibers comprise an elastomeric component such as block copolymers derived from styrene-butadiene systems, such as styrene-ethylene-butylene-styrene (SEBS), styrene-butadiene-styrene (SBS), styrene-isoprene. -styrene (SIS) and similar. Useful block copolymers can also be polyether block copolymers (e.g., PEBAX), copolyester polymers, polyester / polyether block polymers, and the like.

When applied to a tissue of tissue, it is believed that meltblown fibers can reduce the detachment by at least 30% in accordance with the Sutherland rub test. Melt-blown fibers can also reduce the coefficient of friction on the side of the fabric being treated.

In order to better bind the meltblown fibers to the tissue, especially when the tissue is wet, the tissue may contain a holding agent. In one embodiment, the fastening agent may comprise a silicon, an emollient, a binder, binder fibers, a size agent, filler particles, and the like. In an alternative embodiment, the fastening agent may comprise synthetic fibers. The synthetic fibers can be homogeneously mixed with pulp fibers to form the tissue of the tissue. Exemplary synthetic fibers include bicomponent binder fibers and fibers made from any of the polymer systems mentioned herein for use as melt blown materials, such as ethylene vinyl acetate polymers. Alternatively, the tissue can be made from a stratified fiber supply having an outer layer containing the synthetic fibers. Synthetic fibers may be present in the tissue of tissue in an amount of up to about 20% by weight, such as less than about 10% by weight or less than about 5% by weight. In another embodiment, the tissue of tissue is substantially free of synthetic fibers.

As described above, in addition to the tissue tissues, other materials containing pulp fibers can also be treated in accordance with the present invention. For example, in an alternative embodiment, the non-woven fabric may comprise a coform fabric containing a mixture of pulp fibers and polymer fibers. The coform fabric may contain pulp fibers, for example, in an amount greater than about 40% by weight, such as from about 50% to about 80% by weight. The polymer fibers may comprise melt blown fibers made of a polyolefin polymer.

When it comes to a coform fabric, the meltblown fibers applied to the fabric are made of a polymer that is compatible with the polymeric fibers contained within the coform fabric. For example, melt blown fibers can be made of a polyolefin polymer.

The coform fabrics made in accordance with the present invention can be used in numerous applications. In a particular embodiment, for example, the coform fabric can be used to produce a wet cleaning cloth that is previously saturated with a cleaning solution. For example, in a particular embodiment, the wet cleaning cloth comprises a first coform fabric, a second coform fabric, and an elastic layer placed between the first coform fabric and the second coform fabric. Each of the coform fabrics can be treated with meltblown fibers in accordance with the present invention. In particular, the coform fabrics are treated on the side of the fabric that forms an outer surface of the laminate bonded by stretching.

Of particular advantage, it has been discovered that coform fabrics can be treated with meltblown fibers in accordance with the present invention without significantly adversely affecting the softness properties and fabric cleaning properties. For example, coform fabrics treated in accordance with the present invention may have a collision rate of less than 150 grams per centimeter, such as less than about 125 grams per centimeter. The coform fabrics can also have a density of less than about 0.08 grams per cubic centimeter, such as less than about 0.07 grams per cubic centimeter.

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

BRIEF DESCRIPTION OF THE DRAWINGS A complete and authoritative description of the present invention, including the best mode thereof for one with ordinary skill in the art, is more particularly established in the specification, including references to the accompanying Figures in which: Figure 1 is a flowchart of an embodiment of a process for making paper that can be used in the present invention; Figure 2 is a schematic diagram of an embodiment of a method for applying meltblown fibers to a non-woven fabric in accordance with the present invention; Figure 3 is a schematic flow chart of an embodiment of a process for applying meltblown fibers to a coform fabric in accordance with the present invention; Figure 4 is a schematic flow chart of an embodiment of a process for forming laminates bonded with stretch in accordance with the present invention; Y Figure 5 is a perspective view of an embodiment of a process for forming an elastic layer for use in laminates made in accordance with the present invention.

The repeated use of reference characters in the present specification and drawings are intended to represent the same or analogous features or elements of the present invention.

DETAILED DESCRIPTION OF THE INVENTION It should be understood by one of ordinary skill in the art that the present disclosure is a description of exemplary embodiments only, and is not intended as limiting the broad aspects of the present invention.

In general, the present invention is directed to a process for reducing lint and peel levels in non-woven fabrics containing pulp fibers. In accordance with the present invention, a relatively small amount of a polymeric material is applied to at least one surface of a nonwoven fabric in order to reduce lint and detachment. The polymeric material can be in the form of fibers or drops. In a particular embodiment of the present invention, for example, a plating comprising melt blown fibers is applied to at least one side of the nonwoven fabric.

At very low levels of addition, it has been found, for example, that meltblown fibers can be applied to a non-woven fabric to reduce lint and detachment without adversely affecting many other properties of the material. In fact, in some embodiments, melt blown fibers are not discernible, and can still reduce the release levels by more than 30%.

In general, any nonwoven material containing pulp fibers can be treated in accordance with the teachings of the present invention. For example, the non-woven material may be a tissue of tissue, such as a facial tissue, a bath tissue, paper towel, napkin, industrial cleaning cloth, and the like. The tissue of tissue, for example, can have a basis weight from about 10 grams per square meter to about 150 grams per square meter. Bath tissues and facial tissues, for example, have a basis weight from about 10 grams per square meter to about 35 grams per square meter. Paper towels and other cleaning cloth products, however, have a basis weight from about 40 grams per square meter to about 80 grams per square meter.

In addition to tissue tissues, the present invention is also particularly suitable for reducing the lint and release levels in composite tissues, such as coform tissues. In fact, coform fabrics can be made in accordance with the present invention which has reduced lint and peel levels while still having a low collision rate, a low density, and maintain a desired level of strength and resistance to tearing. In addition, coform fabrics made in accordance with the present invention can in fact exhibit a surface having a low coefficient of friction. Therefore, when used as a cleaning cloth product, the fabrics have a greater tendency to slide through an adjacent surface which may be, for example, a back cover or a skin of the wearer.

Particular examples of non-woven materials made in accordance with the present invention will now be described in greater detail. First, a tissue of tissue made in accordance with the present invention will be described followed by a description of a coform tissue. It should be understood, however, that other non-woven materials containing pulp fibers can be treated in accordance with the present invention.

Tissue Products In one embodiment, the present invention is directed to a tissue product having reduced lint and peel levels. In accordance with the present invention, at least one side of the tissue product is treated with a relatively small amount of a polymeric material which, while hardly discernible, significantly decreases the lint and peel levels. In a particular embodiment, for example, the polymeric material is applied using a meltblown matrix. In other embodiments, the polymeric material can be applied using other techniques, such as being printed on the tissue of tissue.

Any variety of materials can also be used to form the tissue tissues of the tissue product. For example, the material used to make the tissue product may include fibers formed by a variety of pulping processes, such as kraft pulp, sulfite pulp, thermomechanical pulp, etc. The pulp fibers may include softwood fibers having an average fiber length of more than 1 millimeter and particularly from about 2 to 5 millimeters based on an average length by weight. Such soft wood fibers may include, but are not limited to, soft northern wood, soft southern wood, redwood, red cedar, spruce, pine (for example, southern pines), red spruce (for example black spruce), combinations of them, and similar. Exemplary commercially available pulp fibers suitable for the present invention include those of Kimberly-Clark Corporation under the brand designations of "Longlac 19".

Hardwood fibers, such as eucalyptus, maple, birch, poplar, and the like, can also be used. In certain aspects, the eucalyptus fibers may be particularly desired to increase the softness of the fabric.

Eucalyptus fibers can also improve brilliance, increase opacity, and change the pore structure of tissue to increase its transmission capacity. In addition, if desired, secondary fibers obtained from recycled materials can be used, such as fiber pulp from sources such as, for example, recycled materials can be used, such as, for example, newspaper, recycled cardboard, and office waste. In addition, other natural fibers can also be used in the present invention, such as abaca, sabai grass, milkweed fluff, pineapple leaf, and the like.

In addition, in some instances, synthetic fibers can also be used. Some suitable synthetic fibers can include, but are not limited to, rayon fibers, ethylene vinyl alcohol copolymer fibers, polyolefin fibers, polyesters, and the like. As "agui" is used, "synthetic fibers" refer to man-made polymeric fibers, which may comprise one or more polymers, each of which may have generated from one or more monomers. The polymeric materials in the synthetic fibers can independently be thermoplastic, thermo-fixed, elastomeric, non-elastomeric, crimped, substantially uncurled, colored, uncoloured, filled with fillers, or unfilled, birefringent, circular in cross section , multi-lobed or otherwise circular in cross section, etc. Synthetic fibers can be produced by any known technique. The fibers Synthetics can be monocomponent fibers such as polyester filaments, polyolefins or other thermoplastic materials, or they can be bicomponent or multicomponent fibers. When more than one polymer is present in a fiber, the polymers can be mixed, segregated into microscopic or macroscopic phases, present side by side or in sheath and core structure, or distributed in any manner known in the art.

Synthetic bicomponent fibers suitable for use in connection with this invention and their manufacturing methods are well known in the polymer field, such as fibers with polyester cores and polyolefin sheaths useful as heat activated binder fibers. Other useful bicomponent fibers are described in, for example, U.S. Patent No. 3,547,763, issued December 15, 1970 to Hoffman, Jr., which describes a bicomponent fiber having a modified helical curl. In addition, the patent of the United States of America number 3,418,199 granted on December 24, 1968 to Anton and others, describes a bicomponent nylon filament capable of curling; U.S. Patent No. 3,454,460 issued July 8, 1969 to Bosely, discloses a bicomponent polyester textile fiber; U.S. Patent No. 4,552,603 issued November 12, 1985 to Harris et al. describes a method for making bicomponent fibers comprising a latent adhesive component for form interfilament joints with the application of heat and a subsequent cooling; and U.S. Patent No. 4,278,634 issued July 18, 1980 to Zwick et al., discloses a method of melt spinning to make bicomponent fibers. All these patents are incorporated herein by reference. The principles of incorporating synthetic fibers into the wet laid tissue are disclosed in U.S. Patent No. 5,019,211, "Tissue Fabrics Containing Curly Sensitive Bicomponent Synthetic Temperature Fibers" issued May 28, 1991 to Sauer, aguí incorporated by reference in its entirety; and U.S. Patent No. 6,328,850, "Layered Tissue Having Improved Functional Properties," granted December 11, 2001, to Phan, incorporated herein by reference to the extent that it is not contradictory to this.

The tissue products made in accordance with the present invention can be made from a single stratum or can be made from multiple strata of tissue tissues. Each stratum can also be formed from a homogeneous blend of fibers or can be made from a stratified fiber supply, the tissue tissue includes at least two layers of fibers. For example, in one embodiment, the tissue may include a middle layer placed between a first outer layer and a second outer layer. Different types of fiber can be incorporated into the individual layers to change the properties of the fabric. For example, in an embodiment, a tissue tissue can be formed where the outer layers include eucalyptus fibers and the inner layer includes soft wood fibers. In an alternative embodiment, the outer layers may contain soft wood fibers and the inner layer may contain eucalyptus fibers.

A tissue product made in accordance with the present invention can generally be formed in accordance with a variety of paper making processes known in the art. In fact, any process capable of making a paper web can be used in the present invention. For example, a papermaking process of the present invention may use wet pressure, creping, continuous air drying, air drying in a creped continuous manner, air drying in a continuous non-creping manner, a single re-creping, double re-creped, calendered, etched, placed by air, as well as other steps in the processing of tissue paper. For example, processes for making paper suitable for forming a tissue tissue are described in U.S. Patent Nos. 5,129,988 issued to Farrington Jr .; 5,494,554, granted to Edwards and others; and 5,529,665 issued to Kaun, which are hereby incorporated in their entirety by reference thereto for all purposes.

A particular embodiment of the present invention utilizes a non-creped continuous air drying technique to form the tissue. Continuous air drying can increase the volume and softness of the tissue. Examples of such a technique are described in the patents of the United States of America numbers 5,048,589 granted to Cook et al .; 5,399,412 issued to Sudall and others; 5,510,001 granted to Hermans and others; 5,591,309 issued to Rugowski and others; 6,017,417 granted to Wendt and others, and 6,432,270 granted to Liu and others, which are incorporated here in their entirety by reference to it for all purposes. Air drying continuously without creping generally involves the steps of: (1) forming a supply of cellulose fibers, water, and optionally, other additives; (2) deposit the supply on a foraminous band that moves, thus forming a fibrous tissue on the foraminous band that moves; (3) subjecting the fibrous tissue to air drying in a continuous manner to remove water from the fibrous tissue; and (4) removing the dried fibrous tissue from the foraminous band that is displaced.

For example, with reference to Figure 1, an embodiment of a papermaking machine that can be used in forming an air-dried tissue product continuously without creping is illustrated. For simplicity, the various tension rolls schematically used to define the various runs of the fabric are shown but not numbered. As shown, a main box for making paper 1 can be used to inject or deposit a jet of an aqueous suspension of fibers to make paper on an inner forming fabric 3 as it passes through forming roll 4. external formation 5 serves to contain the fabric 6 while passing over the forming roll 4 and while spilling some of the water. If desired, the dewatering of the wet fabric 6 can be carried out, such as by vacuum suction, while the wet fabric 6 is supported by the forming fabric 3.

The wet fabric 6 is then transferred from the forming fabric 3 to a transfer fabric 8 while having a solid consistency from about 10% to about 35%, and particularly, from about 20% to about 30%. As used herein, a "transfer fabric" is a fabric that is placed between the forming section and the drying section of the fabric manufacturing process. The transfer fabric 8 can be a pattern fabric having protrusions or knuckles for printing, such as those described in U.S. Patent No. 6,017,417 issued to Wendt et al. Typically, the transfer fabric 8 travels at a slower speed than the forming fabric 3 to improve "stretching in the machine direction" of the fabric, which generally refers to the stretching of a fabric in its fabric or direction. length (expressed as the percentage of elongation in sample failure). For example, the relative speed difference between the two fabrics can be from 0% to about 80%, in some embodiments, greater than about 10%, in some embodiments, from about 10% to about 60%, and in some additions, from around 15% to around % This is commonly referred to as a "rushed transfer". A useful method of performing the expedited transfer is taught in the United States of America patent number 5,667,636 granted to Engel et al., Which is incorporated in its entirety by reference to the same for all purposes.

The transfer to the fabric 8 can be carried out with the assistance of positive and / or negative pressure. For example, in one embodiment, a vacuum shoe 9 can apply negative pressure in such a way that the forming fabric 3 and the transfer fabric 8 simultaneously converge and diverge at the leading edge of the vacuum slot. Typically, the vacuum shoe 9 supplies pressure at levels from about 10 to about 25 inches of mercury. As noted above, the vacuum transfer shoe 9 (negative pressure) can be supplemented or replaced by the use of positive pressure from the opposite side of the fabric to blow the fabric onto the next fabric. In some embodiments, other vacuum shoes may also be used to assist in removing the fibrous tissue 6 on the surface of the transfer fabric 8.

From the transfer fabric 8, the fibrous fabric 6 is then transferred to the drying cloth in a continuous form 11 with the aid of a vacuum transfer roller 12. While it is supported by the drying fabric in continuous form 11, the fabric 6 is then dried by a dryer in continuous form 13 to a solids consistency of about 90% or greater, and in some embodiments, to about 95% or greater. The continuous dryer 13 achieves the removal of moisture by passing air through without applying any mechanical pressure. Continuous drying can also increase the volume and softness of the fabric. In one embodiment, for example, the continuous dryer 13 may contain a perforated, rotatable cylinder and a hood for receiving hot air blown through cylinder bores as the continuous drying fabric 11 carries the fabric 6 over the top of the cylinder. The heated air is forced through the perforations in the dryer cylinder in continuous form 13 and removes the rest of the water from the fabric 6. The temperature of the air forced through the fabric 6 by the dryer in continuous form 13 may vary, but it is typically from around 100 degrees centigrade to around 250 degrees centigrade. There may be more than one dryer continuously in series (not shown), depending on the speed and capacity of the dryer.

As it moves through the dryer in continuous form 13, as described above, the fabric 6 is supported by the drying fabric in continuous form 11. In some embodiments, the fabric is pressed against the drying fabric continuously in a way that causes an impression of the drying cloth continuously to remain in the fabric after the drying process. In these additions, There may be a noticeable difference between the fabric side of the fabric and the air side of the fabric. The side to the fabric of the fabric is the side of the fabric supported by the fabric of drying in continuous form, while the side to the air of the fabric is the opposite side of the fabric.

It should also be understood that other methods of non-compressive drying, such as microwave or infrared heating, can be used. In addition, compressive drying methods, such as drying with the use of a Yankee dryer, can also be used in the invention.

The dried tissue sheet 15 is then transferred to a first dry end transfer cloth 16 with the aid of a vacuum transfer roller 17. The tissue sheet shortly after transfer is sandwiched between the first end transfer fabric echo 16 and a transfer band 18 to positively control the trajectory of the sheet. The air permeability of the transfer belt 18 may be lower than that of the first dry end transfer cloth 16, causing the sheet to naturally adhere to the transfer belt 18. At the separation point, the sheet 15 follows the transfer band 18 due to vacuum action. Suitable low air permeability fabrics for use as the transfer belt 18 include, without limitation, the Mononap NP50 COFPA dryer felt (air permeability of about 50). cubic feet per minute per square foot) and Asten 960C (waterproof to air). The transfer belt 18 passes over two winding drums 21 and 22 before returning to again pick up the dried tissue sheet 15. The sheet 15 is transferred to a parent roller 25 at a point between the two winding drums. The parent roller 25 is wound onto the winder reel 26, which is driven by a central drive motor.

If desired, various papermaking additives can be applied to the fabric during formation. For example, in some embodiments, a wet strength agent may be used, to increase the strength of the tissue product. As used herein, a "wet strength agent" is any material that, when added to the cellulose fibers, can provide a resulting fabric or sheet with a geometric tensile strength to geometric tensile strength in excess of about of 0.1. Typically these materials are referred to as either "permanent" wet strength agents or "temporary" wet strength agents. As is well known in the art, temporary and permanent wet strength agents can also sometimes function as dry strength agents to improve the strength of the tissue product when it is dry.

Suitable permanent wet strength agents are typically polymeric or oligomeric resins cationic, water-soluble, which are capable of either cross-linked with themselves (homo-linked cross-linked) or with cellulose or other constituents of wood fiber. Examples of such compounds are described in U.S. Patent Nos. 2,345,543 issued to Wohnsiedler et al .; 2,926,116 awarded to Keim; and 2,926,154 granted to Keim, which are hereby incorporated in their entirety by reference thereto for all purposes. One class of such agents includes polyamine-epichlorohydrin, polyamide epichlorohydrin, or polyamide-amine-epichlorohydrin resins, collectively referred to as "PAE resins" (polyamide epichlorohydrin). Examples of these materials are described in US Pat. Nos. 3,700,623 issued to Keim, and 3,772,076 issued to Keim, which are hereby incorporated by reference in their entirety for all purposes and sold by Hercules, Inc., of Wilmington, Delaware, under the brand name of "Kymene", for example, Kymene 557H or 557LX. The Kymene 557 LX, for example, is a polyamide epichlorohydrin polymer containing both cationic sites, which can form bonds with anionic groups on the pulp fibers, and azetidinium groups, which can form covalent bonds with the carboxyl groups on the pulp fibers and bonded in cross-shaped with the polymer column when it is cured. Other suitable materials include polyamide epichlorohydrin resins with activated base, which are described in the patents of the United States of America numbers 3,885,158 granted to Petrovich; 3,899,388 granted to Petrovich; 4,129,528 granted to Petrovich; 4,147,586 granted to Petrovich; and 4,222,921 granted to van Eanam, which are incorporated herein in their entirety by reference to it for all purposes. Polyethyleneimine resins may also be suitable for immobilizing fiber-to-fiber bonds. Another class of wet strength agents of the permanent type include aminoplast resins (for example, urea-formaldehyde and melamine-formaldehyde).

Temporary wet strength agents may also be useful in the present invention. Suitable temporary wet strength agents can be selected from agents known in the art such as dialdehyde starch, polyethylene imine, mangalactam gum, glyoxal, and dialdehyde mangalactan. Also useful are the glyoxylated vinyl amide wet strength resins as described in U.S. Patent No. 5,446,337 issued to Darlington et al., Which is hereby incorporated by reference in its entirety for all purposes. Useful water-soluble resins include polyacrylamide resins such as those sold under the Parez brand, such as Parez 631NC, by American Cyanamid Company, of Stanford, Connecticut. Such resins are generally described in the patents of the United States of America numbers 3,556,932 granted to Coscia and others; and 3,556,933 granted to Williams and others, which are herein incorporated in their entirety by reference thereto for all purposes. For example, the resins "Parez" typically they include a polyacrylamide-glyoxal polymer containing cationic hemiacetal sites which can form ionic bonds with carboxyl or hydroxyl groups present on the cellulose fibers. These bonds can provide increased resistance to the tissue of the pulp fibers. In addition, because the hemiacetal groups are readily hydrolyzed, the wet strength provided by such resins is primarily temporary. U.S. Patent No. 4,605,702 issued to Guerro et al., Which is hereby incorporated by reference in its entirety for all purposes, also discloses suitable temporary wet strength resins made by the reaction of a polymer of vinyl amide with glyoxal, and then subjected the polymer to a water-based treatment. Similar resins are also disclosed in U.S. Patent Nos. 4,603,176 issued to Bjorkquist et al .; 5,935,383 issued to Sun and others; and 6,017,417 granted to Wendt and others, which are not incorporated here in their entirety by reference to it for all purposes.

A chemical binder can also be applied to soften the tissue. Specifically, a chemical binder can reduce the amount of hydrogen bonds within one or more layers of the fabric, which results in a softer product. Any material that can be applied to cellulose fibers and that is capable of improving the soft feel of a tissue by interrupting hydrogen bonding can generally used as a binder in the present invention. In particular, it is typically desired that the binder possess a cationic charge to form an ionic bond with the anionic groups present in the cellulose fibers. Examples of suitable cationic deagglutinants may include, but are not limited to, quaternary ammonium compounds, imidazolinium compounds, bis-imidazolinium compounds, dicuaternary ammonium compounds, polyquaternary ammonium compounds, functional ester quaternary ammonium compounds (e.g. quaternized fatty acid trialkanolamine ester), phospholipid derivatives, polydimethylsiloxanes and cationic and nonionic related silicon compounds, fatty acid derivatives & carboxylic, derivatives of mono and polysaccharide, polyhydroxy hydrocarbons, etc. For example, some suitable debonders are described in U.S. Patent Nos. 5,716,498 issued to Jenny et al.; 5,730,839 granted to Wendt and others; 6,211,139 issued to Keys and others; 5,543,067 issued to Phan and others; and WO / 0021918, which are incorporated herein in their entirety by reference thereto for all purposes. For example, the Jenny et al. And Phan et al. Documents disclose various functional ester quaternary ammonium binder (e.g., quaternized fatty acid trialkanolamine ester salt salts) suitable for use in the present invention. In addition, Wendt et al. Disclose quaternary imidazolinium binder which may be suitable for use in the present invention. In addition, Keys et al. Describe polyquaternary ammonium binder polyester which may be useful in the present invention. Still other suitable debonders are disclosed in U.S. Patent Nos. 5,529,665 issued to Kaun and 5,558,873 issued to Funk et al., Which are hereby incorporated by reference in their entirety for all purposes. In particular, Kaun describes the use of various cationic silicon compositions as softening agents.

In accordance with the present invention, after the fabric 15 as shown in Figure 1 is formed, the fabric is treated with a polymeric material in order to decrease lint and detachment. The polymeric material can be applied to the fabric 15 using various techniques. For example, in an embodiment, drops of the polymeric material can be spread on the tissue surface using any suitable device. For example, the polymeric material can be printed on the fabric. In an alternative embodiment, however, the polymeric material is supplied through a meltblown matrix that forms meltblown fibers that are directed onto the fabric 15.

The polymeric material can be applied to the fabric after the fabric has been substantially dried. Therefore, as shown in Figure 1, the polymeric material can be applied at any suitable point between the dryer in continuous form 13 and spool 26. Alternatively, the polymeric material can be applied in an off-line process.

For example, with reference to Figure 2, it is shown in an embodiment of a method for applying a polymeric material to a tissue of tissue. As illustrated, a parent roller 30 is unrolled and passed, optionally, through a calender pressure point formed between the calender roll 32 and a calender roll 34. The calendered fabric is then passed below a die. blown with fusion 38 where the polymeric material is applied to the fabric. After being applied to the fabric, the tissue is then passed to a wire feeder where the fabric is wound on logs 36 and cut into, for example, tissue rolls.

The polymeric material is applied to the tissue of tissue 15 in relatively smaller amounts. For example, meltblown fibers can be applied to the tissue of tissue 15 in an amount of less than about 6 grams per square meter, such as less than about 4 grams per square meter, and still less than about 2 grams per square meter. grams per square meter. For example, in some embodiments, the lint and peel levels can be reduced by applying meltblown fibers in an amount of less than about 1 gram per square meter.

The melt blown fibers deposited on the fabric may have a size and a shape that varies depending on the polymeric material used. For example, melt blown fibers may comprise continuous filaments having a diameter of less than about 10 microns, such as less than about 5 microns.

Once applied to tissue 15, meltblown fibers are able to significantly reduce lint and detachment. For example, in some embodiments, the release levels can be reduced by more than 30% in accordance with the Sutherland rub test. In addition to reducing lint and detachment, meltblown fibers may also have a tendency to lower friction coefficients of the fabric surface. Therefore, when the tissue is rubbed against the skin, the tissue may feel softer or smoother.

Several different materials can be used and deposited on the tissue of tissue. In general, any suitable polymeric material can be deposited on the fabric which is capable of reducing lint and detachment and which also binds the fibers contained within the fabric, especially when the fabric is wet. Polymeric materials that can be used include thermo-fixed polymers, thermoplastic polymers, photo-cure polymers, and waxes, such as paraffin waxes.

In one embodiment, the polymer composition applied to the tissue comprises a hot melt material. Such materials include, but are not limited to, styrene-butadiene anionic copolymers, polyvinyl acetate homo-polymers, vinyl-ethylene acetate copolymers, vinyl-acrylic acetate copolymers, ethylene-vinyl chloride copolymers, vinyl acetate-vinyl chloride-ethylene terpolymers, polymers polyvinyl chloride acrylic, acrylic polymers, nitrile polymers, and any other suitable anionic latex polymers known in the art. Other examples of suitable latexes may be described in US Pat. No. 3,844,880 issued to Meisel Jr., et al., Which is hereby incorporated by reference in its entirety for all purposes.

Particular examples of polymeric materials that can be used in accordance with the present invention include ethylene vinyl acetate copolymers and ethylene vinyl alcohol polymers.

In other embodiments, various thermoplastic or elastomeric polymers can be supplied to the meltblown matrix 38 as shown in Figure 2, and converted into meltblown fibers to deposit on the tissue of tissue 15. For example, such polymeric materials include polyolefins, polyesters, and block copolymers, such as styrene-butadiene copolymers. Polyolefin polymers include polypropylene and polyethylene homo-polymers and copolymers.

In order to better adhere or bind the meltblown fibers to the tissue of tissue 15, in one embodiment, various fasteners may be incorporated into the fabric to bond with the polymeric material. In general, the fastening agent can be any suitable material that is compatible with the polymeric material used to form the meltblown fibers. For example, in one embodiment, the synthetic fibers can be incorporated into the tissue of tissue. Synthetic fibers can be incorporated into the tissue of tissue in amounts of less than about 105 by weight. When present, the synthetic fibers bind the meltblown fibers while they remain buried in the fabric to help bind the blown fibers to the fabric. Synthetic fibers may comprise, for example, polyolefin fibers, such as polyethylene fibers and / or polypropylene fibers, polyester fibers, nylon fibers, or impregnated latex polymers. The synthetic fibers may also comprise bicomponent fibers such as sheath and core fibers. Such bicomponent fibers can include, for example, polyethylene / polypropylene fibers, polypropylene / polyethylene fibers, or polyethylene / polyester fibers.

In addition to the synthetic fibers, various other fastening agents may be used in accordance with the present invention. Such other holding agents include incorporating silicon, binder, hydrophobic particles, emollients, size agents, filler particles, and the like into the tissue tissue.

In order to make the available fastening agents to the meltblown fibers, the fastening agents can also be incorporated into the tissue of the tissue 15 so as to be present in greater quantities on the surfaces of the fabric. For example, in one embodiment, a stratified fiber supply may be used to form the tissue of tissue 15. The stratified fiber supply may include at least one outer layer containing a binding agent, such as synthetic fibers.

In the embodiment illustrated in Figure 2, only one side of tissue 15 is being treated in accordance with the present invention. In this embodiment, for example, the tissue of tissue 15 can be a continuous dried, non-creped fabric, and the meltblown fibers can be applied to the air side of the fabric, where greater lint or detachment can occur. In other embodiments, however, it should be understood that the polymer composition, such as meltblown fibers, can be applied to both sides of the tissue tissue.

The tissues of tissue made in accordance with the above process can be used in an almost unlimited variety of applications. For example, tissue tissues can be used to produce facial tissues, bath tissues, paper towels, industrial cleansing wipes, and the like. The tissue products may be single-layer products, or products of multiple strata. In addition to the foregoing, tissue tissues may also be incorporated into absorbent articles or may be used in various other applications, such as for use on table tops, drawer and cabinet liners, refrigerator liners, surgical seals, and the like.

Products that contain Coform Fabrics In addition to tissue tissues, the teachings of the present invention are also well suited for reducing lye and eschar levels in coform tissues. In particular, it was discovered that a very light treatment of blown fibers with fusion to a coform fabric can reduce the levels of lint and eschar while maintaining tissue flexibility. In fact, and since the meltblown fibers can be applied to such low amounts, the softness of the fabric is not substantially affected. For example, coform fabrics made according to the present invention can have a cup crush of less than about 150 g / cm, such as less than about 125 g / cm. In others In addition, it is believed that cup crush of coform fabrics made in accordance with the present invention may be less than 120 g / cm or less than about 115 g / cm. In fact, meltblown fibers have also been found to lower the coefficient of friction on the treated side of the fabric allowing the coform fabric to glide more easily across the surfaces, which further reduces the lint and further enhances the perceived softness of the tissue.

The density of coform tissues made according to the present invention can also be relatively low. For example, the density may be less than about 0.08 grams per cubic centimeter, such as less than about 0.07 grams per cubic centimeter.

Referring to Figure 3, an embodiment of the process for forming the coform tissues according to the present invention is shown. The coform fabrics are made of microfibers formed by extrusion processes such as, for example, meltblowing processes or spinning processes. In an embodiment illustrated in Figure 3, the thermoplastic polymer microfibers are formed from extruder banks generally 50, comprising, in this embodiment, meltblown extruders 52. The microfibers are blended with individualized wood pulp fibers that exit a pulp generator 54. Although two melt blowing extruders are shown 52 in Figure 3, it should be understood that more or less extruders can be used.

From the extruders 52 and the pulp generator 54, a coform fabric 58 is created on the forming surface 56. The coherent delivered fibrous structure 58 can be formed by the microfibers and the wood pulp fibers without any adhesive, molecular or hydrogen between the two different types of fibers. The wood pulp fibers are preferably evenly distributed through the microfiber matrix to provide a homogeneous material. The material is formed by initially forming a primary air stream containing the melt blown microfibers, forming a secondary air stream containing the wood pulp fibers, fusing the primary and secondary streams under turbulent conditions to form a stream of integrated air containing a complete mixture of the microfibers and the wood pulp fibers, and then directing the integrated air stream over the forming surface 56 to air-form the fabric-type material. The microfibers are in a nascent state condition at high temperatures when they are mixed turbulently with the wood pulp fibers in the air.

In one embodiment, the coform layer or layers may have from about 20-50% by weight of polymer fibers and about 80-50% by weight of pulp fibers. For example, the ratio of polymer fibers to pulp fibers can be from about 25-40% by weight of polymer fibers and from about 75-60% by weight of pulp fibers. In another embodiment, the ratio of polymer fibers to pulp fibers can be from about 30-40% by weight of pulp fibers and from about 70-60% by weight of pulp fibers. For example, the ratio of pulp fibers to polymer fibers can be about 35% by weight of the polymer fibers and about 65% by weight of pulp fibers.

Non-limiting examples of the polymers suitable for forming the coform fabrics are polyolefin materials such as, for example, polyethylene, polypropylene and polybutylene, including copolymers of ethylene, polypropylene copolymers and butylene copolymers thereof. A particularly useful polypropylene is Basell PF-105. Additional polymers are described in U.S. Patent No. 5,385,775 issued to Wright.

Fibers of various natural origin are applicable to the invention. Digested cellulose fibers from softwood (derived from coniferous trees), from hardwood (derived from deciduous trees) or cotton lint can be used. The grass fibers Esparto, bagasse, hemp and of flax and other sources of lignite and cellulose fibers can also be used as raw material in the invention. For reasons of cost, ease of manufacture and availability, in one embodiment, the fibers are those derived from wood pulp (for example, cellulose fibers). A commercial example of such wood pulp materials is available from Weyerhaeuser as CF-405. Other commercially available pulp materials include Georgia Pacific Beige Pulp Isles Pulp, ITT Rayonier ngel Treated Pulp, ITT Rayonier White Jade Treated Pulp, and Coosa Treated Pulp CR-56. Generally, wood pulps can be used. Applicable wood pulps include chemical pulps, such as Kraft (for example, sulfate) and sulfite pulps, as well as mechanical pulps including, for example, ground wood, thermomechanical pulp (for example, TMP) and quimotermomechanical pulp ( for example, CTMP). Fully bleached, partially bleached and unbleached fibers are also useful here. It may often be desired to use the bleached pulp for superior brilliance and consumer appeal.

Also useful in the present invention are fibers derived from recycled paper, which may contain any or all of the above categories as well as other non-fibrous materials such as fillers and adhesives used to facilitate the process of making original paper.

As shown in Figure 3, the coform fabric 58 according to the present invention is contacted with a relatively small amount of meltblown fibers being emitted by a meltblown extruder 60. The meltblown fibers which leaving the extruder 60 are distributed on the surface of the coform fabric 58 and serve to reduce the levels of lint and eschar. The present inventors have discovered that even very small amounts of meltblown fibers distributed on the surface of the coform fabric significantly decrease the formation of threads and eschar.

For example, the meltblown fibers are emitted by the extruder 60 and may be presented on the coform fabric 58 in an amount of less than about 8 grams per square meter, such as less than about 6 grams per square meter, such as less than about 4 grams per square meter. For example, in one embodiment, meltblown fibers may be present on the coform fabric 58 in an amount of from about 2 grams per square meter to about 4 grams per square meter.

To the above amounts, the meltblown fibers decrease the lye and eschar levels without substantially adversely affecting the flexibility and softness.

In addition, meltblown fibers can decrease the coefficient of friction of a tissue surface.

The meltblown extruder 60 as shown in Figure 3 generally extrudes a thermoplastic polymer resin through a plurality of small diameter capillaries of a meltblown die as melted yarns into a stream of heated gas on the which is flowing in the same direction as that of the extruded yarns so that the extruded yarns are attenuated, for example, pulled or stretched to reduce their diameter. Such meltblowing techniques are discussed, for example in U.S. Patent Number 4,663,220 issued to Wisneski, and others which is incorporated herein by reference.

The melt blown fibers exiting the extruder 60 are shown in Figure 3 and can, for example, be in the form of continuous filaments. The filaments may have a diameter such as less than about 10 microns. For example, the diameter of the filaments may be from about 3 microns to about 7 microns.

In general, any polymeric material capable of binding the coform fabric 58 can be extruded from the meltblown extruder 60. Such polymers can include, for example, polyolefins, such as polypropylene and polyethylene. The polymer composition may also comprise copolymers of polyolefin. In one embodiment, the polyolefin can be catalyzed with metallocene, such as metallocene-catalyzed polyethylene. Such polymers are commercially available from Montell and Dow Chemical.

As shown in Figure 3, the meltblown fibers exiting the extruder 60 are applied to the upper surface of the coform fabric 58. In an alternate embodiment, however, the meltblown fibers can first be deposited on the forming surface 56 and the coform fabric 58 can subsequently be applied to the forming surface. Further, in the embodiment illustrated in Figure 3, only a single side of the coform fabric 58 is being treated with the meltblown fibers. It should be understood, however, that in other embodiments both sides of the coform fabric can be similarly treated with meltblown fibers. For example, in one embodiment, the meltblown fibers can be applied to the forming surface 56 followed by the coform fabric 58 and then followed by an additional deposit of meltblown fibers to treat each side of the coform fabric.

The coform fabrics made according to the present invention can be used in numerous applications. The coform fabrics can have a basis weight, for example, from about 10 grams per square meter to about 200 grams per square meter. More particularly, the tissues coform can have a basis weight, for example, from about 10 grams per square meter to about 30 grams per square meter. The coform fabrics can be used, for example, as a cleaning product. In an alternate embodiment, the coform fabric can be used as an absorbent layer in a disposable absorbent product. In this embodiment, the coform fabric may contain super absorbent particles. In yet another embodiment of the present invention, the coform tissue can be used in medical applications, such as a surgical cover, a bandage and the like.

The coform fabrics made in accordance with the present invention can be used alone in a single stratum construction or can be combined with other materials to form the laminates.

In a particular embodiment of the present invention, the coform fabric is pre-saturated with a cleaning solution and used as a wet cleaning cloth. The cleaning solution can be any liquid which can be absorbed into the coform material to provide the desired cleaning properties. For example, the cleaning solution may include water, an alcohol, emollients, surfactants, fragrances, preservatives, chelating agents, pH buffers or combinations thereof. The cleansing solution may also contain lotions and / or medications.

In a particular embodiment, the cleaning solution may contain an anionic sulfosuccinate based on non-irritating or low irritation silicone. Alternatively, the cleaning solution may contain a non-greasy lubricating cleaning auxiliary composed of a non-irritating or low-irritant long chain aliphatic anionic sulfosuccinate. In some other alternative embodiments, the cleaning solution may contain non-irritating or low-irritant hydrophilic emollients. The hydrophilic emollient esters can be combined with an anionic sulfosuccinate. Other optional additives may be contained in the cleaning solution and include solvents, fragrances, preservatives, humectants, and other components for additional skin care benefits, such as relief, cooling, healing, softening, and the like.

In a particular embodiment of the present invention, the cleaning solution may contain a dimethicone copolyol sulfosuccinate in an amount of from about 1% to about 5% by weight, an aliphatic sulfosuccinate in an amount of from about 0.01% to about of 3% by weight and a non-ionic ester emollient in an amount of from about 0.01% to about 2% by weight. The ester emollient may contain halides derived from silicone or aliphatic alkyl. Solvents that can be combined with the above ingredients include water, polyhydroxy compounds such as glycerin, propylene glycol, ethylene glycol, polypropylene glycol, polyethylene glycol, and the like. For the above formulation, other ingredients such as condoms, fragrances, skin care agents such as Vitamin E, aloe vera, chamomile, essential oils, humectants, astringents, anti-irritants, and antioxidants can be added. The cleaning solution can be applied to the coform a from about 200% to about 500% by weight of the base sheet.

In a particular embodiment of the present invention, the coform fabrics made in accordance with the present invention are incorporated into the bonded and stretched laminate to form a previously saturated wet cleaning cloth. The bonded and stretched laminate may include, for example, a first coform fabric, a second coform fabric, and an elastic layer placed between the two coform fabrics. Each of the coform fabrics defines an outer surface of the laminate. Each outer surface can be treated with melt blown fibers according to the present invention to reduce lint and bedsores. An embodiment for forming a stretched-attached laminate according to the present invention is shown in Figure 4. Like reference numerals have been used to indicate similar elements.

As shown in Figure 4, an elastic fibrous fabric 62 is prepared in a fabric forming machine 100, illustrated in detail in Figure 5. The elastic fibrous tissue. 62 passes through an S-roll arrangement 64 before entering a horizontal calendering, having a pattern calendering roll 66 and an anvil roll 68. The calendering roll may have, for example, from about 1 inch. % to about 30% of engraved pin joining area, such as from about 12% to about 14%. Both the anvil and pattern rolls can be heated to provide the thermal point joint. The temperature and clamping point forces required to achieve proper attachment depend on the material being laminated.

A first coform fabric 58A and a second coform fabric 58B are prepared in accordance with the present invention as discussed in detail with respect to Figure 3. In particular, each coform fabric 58A and 58B is treated with an outer surface with a slight amount of fibers blown with fusion to reduce lint and eschar. In the embodiment illustrated in Figure 4, as opposed to the embodiment illustrated in Figure 3, the meltblown extruders 60 are placed upwardly of the coform 50 extruder banks. In this manner, the melt blown fibers are first deposited on the forming surface 58 followed by the formation of coform fabrics 58A and 58B.

The coform fabrics 58A and 58B are passed through the calendering rollers 66 and 68 with the elastic layer 62.

The layers are bonded together within the calendering rolls to form a stretched-attached laminate 70.

As shown in Figure 4, the elastic fabric 62 passes through the S-roll arrangement 64 and into a pressure point 72 formed between the calendering rolls. By controlling the peripheral linear speed of the rollers of the S-roll arrangement relative to the peripheral linear speed of the calendering rolls, the elastic fibrous fabric 62 is tensioned and stretched when the fabric is bonded to the coform fabrics 58A and 58B . Elastic fabric 62 for example, can be stretched in the range of from about 75% to about 300% of its relaxed length. For example, the fabric may be stretched in the range of from about 75% to about 150% of its relaxed length, such as from about 75% to about 100% of its relaxed length.

The laminate 70 is relaxed with the release of the tensioning force by the arrangement of the S-roll and the calendering rolls. When that happens, the coform fabrics 58A and 58B fold into the resulting laminate. The bonded and stretched laminate 70 is then bonded on a furling roll 74. Optionally, the drawn-bonded laminate 70 is activated by heat treatment in a heat activation unit 76. The processes for making the composite elastomeric materials of this type are described in, for example, Patents of the United States of America Nos. 4,720,415 granted to Vander Wielen, et al., 5,385,775 granted to Wright, and in the International Patent Cooperation Treaty Publication Number WO 02/053365 of Lange, and others, which are incorporated herein by reference.

The coform fabrics 58A and 58B can be attached to the elastic fibrous fabric 62 in at least two places by any suitable means such as, for example, thermal bonding or ultrasonic welding which softens at least parts of at least one of the materials, usually the elastic fibrous fabric because the elastomeric materials used to form the elastic fibrous fabric 62 have a softening point lower than the components of the coform layers 58A and 58B. The joint can be produced by applying heat and / or pressure to the overlapped elastic fibrous fabric 62 and to the collapsible layers 58A and 58B by heating these parts (or the superimposed layer) to at least the softening temperature of the material with the softening temperature lower to form a reasonably strong and permanent bond between the smoothed and resolidified portions of the elastic fibrous fabric 62 and the collapsible layers 58A and 58B.

The union roller arrangement 66 and 68 includes a smooth anvil roller 68 and a pattern calendering roller 66 such as, for example, a bolt engraving roller arrangement with a smooth anvil roller. One or both of the roller Smooth anvil and calendering roller can be heated and the pressure between these two rollers can be adjusted by a well-known structure to provide the desired temperature, if any, and pressure bonding to join the collapsible layers to the elastic fibrous fabric. As can be appreciated, the joint between the collapsible layers and the elastic sheet is a point joint. Various bonding patterns may be used depending on the desired tact properties of the final composite laminate. The attachment points are preferably evenly distributed over the joint area of the composite material.

With regard to thermal bonding, one skilled in the art will appreciate that the temperature at which the materials, at least the joined sides thereof, are heated for bonding with heat will depend not only on the temperature of the heated roller or rollers or from other sources of heat, but from the residence time of the materials on the heated surfaces, the compositions of the materials, the base weights of the materials and their specific heats and thermal conductivities. Typically, the bonding can be carried out at a temperature of from about 40 ° to about 80 ° C. For example, the bonding can be carried out at a temperature of from about 55 ° to about 75 ° C. More preferably, the bonding can be carried out at a temperature of from about 60 ° to about 70 ° C. The typical pressure range, on the rollers, It can be from around 18 to around 56.8 kilograms per linear centimeter (KLC). For example, the pressure range, on the rollers, can be from about 18 to about 24 kilograms per linear centimeter (KLC).

In general, any suitable elastic layer can be incorporated into a stretched and joined laminate illustrated in Figure 4. For example, the elastic fabric can be a fabric comprising melt blown fibers or the fabric can contain two or more layers of materials; wherein at least one layer may be a layer of elastomeric meltblown fibers and at least one layer may contain essentially parallel courses of elastomeric fibers autogenously bonded to at least a portion of the elastomeric meltblown fibers. The elastomeric fibers may have an average diameter ranging from about 40 to about 750 microns and extending along a length (eg, in the machine direction) of the fibrous tissue. The elastomeric fibers can have an average diameter in the range of from about 50 to about 500 microns, for example, from about 100 to about 200 microns.

The elastic fibers that extend along the length (for example, in the Machine Direction) of the fibrous tissue increase the tension modulus by about % more than the tension module of the fibrous tissue in the Transverse direction to the machine. For example, the tension modulus of an elastic fibrous fabric can be about 20% to about 90% greater in the Machine Direction than the tension modulus of an essentially isotropic nonwoven fabric having about the same basis weight containing only fibers blown with elastomeric melting. This increased machine tension modulus increases the amount of retraction that can be obtained for a given basis weight of the composite elastic material.

The elastic fibrous fabric may contain at least about 20 percent, by weight, elastomeric fibers. For example, the elastic fibrous fabric may contain from about 20 percent to about 100 percent, by weight, of the elastomeric fibers. Preferably, the elastomeric fibers can constitute from about 20 to about 60 percent, by weight, of the elastic fibrous tissue. More preferably, the elastomeric fibers may constitute from about 20 to about 40 percent, by weight, of the elastic fibrous tissue.

Figure 5 is a schematic view of a system 100 to form an elastic fibrous fabric which can be used as a component of the composite elastic material of the present invention. In the formation the fibers which are used in elastic fibrous tissue, pellets or splinters, etc. (not shown) of an extrudable elastomeric polymer are introduced into the pellet hoppers 100 and 104 of the extruders 106 and 108.

Each extruder has an extrusion screw (not shown) which is driven by a conventional drive motor (not shown). As the polymer advances through the extruder, due to the rotation of the extrusion screw by the drive motor, it is progressively heated to a melted state. The heating of the polymer to the melted state can be achieved in a plurality of discrete steps with its temperature being gradually raised as it passes through the discrete heating zones of the extruder 106 to a melt blowing die 110 and the extruder 108 to a unit continuous filament former 112. The meltblown matrix 110 and continuous filament former unit 112 may still be another heating zone wherein the temperature of the thermoplastic resin is maintained at a high level for extrusion. The heating of the various zones of the extruders 106 and 108 and of the meltblown matrix 110 and of the continuous filament forming unit 112 can be accomplished by any of a variety of conventional heating arrangements (not shown).

The elastomeric filament component of the elastic fibrous fabric can be formed using a variety of extrusion techniques. For example, elastic fibers can be formed using one or more conventional meltblown die units which have been modified to remove the flow of heated gas (e.g., the primary air stream) which generally flows in the same direction as that of the extruded yarns to attenuate extruded threads. This modified meltblown matrix unit 102 usually extends through a perforated collection surface 114 in a direction which is essentially transverse to the direction of movement of the collection surface 114. The modified matrix unit 112 includes a linear array 116 of small diameter capillary vessels aligned along the transverse extension of the matrix with the transverse extension of the matrix being approximately as long as the desired width of the parallel rows of elastomeric fibers to be produced. That is, the transverse dimension of the matrix is the dimension which is defined by the linear array of capillary matrix vessels. Typically, the diameter of the capillary vessels can be in the order of from about 0.025 centimeters to about 0.076 centimeters. Preferably, the diameter of the capillary vessels can be from about 0.0368 centimeters to about 0.0711 centimeters. More preferably, the diameter of the capillary vessels can be from about 0.06 centimeters to about 0.07 centimeters. From about 5 to about 50 such capillary vessels can be provided per linear inch of matrix face. Typically, the diameter of the capillary vessels it can be from around 0.127 centimeters to about 0. 508 centimeters Typically, the length of the capillary vessels can be from about 0.287 centimeters to about 0.356 centimeters of lake. A meltblown matrix can range from about 51 centimeters to about 185 or more centimeters in length in the transverse direction. One familiar with the art will realize that the capillaries may be of a shape other than circular, such as, for example, triangular, rectangular, and the like; and that the spacing or density of the capillary vessels may vary across the length of the matrix.

Since the heated gas stream (e.g., the primary air stream) that flows past the die tip is greatly reduced or absent, it is desirable to isolate the die tip or provide heating elements to ensure that the Extruded polymer remains melted and flowable while at the tip of the matrix. The polymer is extruded from the capillary vessel array 116 in the modified matrix unit 112 to create the extruded elastomeric fibers 118.

The extruded elastomeric fibers 118 have an initial velocity as they leave the array 116 of capillary vessels in the modified matrix unit 112. These fibers 118 are deposited on a perforated surface 114 which it must be moved at at least the same speed as the initial speed of the elastic fibers 118. The perforated surface 114 is an endless belt conventionally driven by rollers .. 120. The fibers 118 are deposited in an essentially parallel alignment on the surface of the endless band 114 which is rotating as indicated by the arrow 122 in Figure 5. The vacuum boxes (not shown) can be used to assist in the retention of the matrix on the surface of the band 114. The The tip of the matrix unit 112 is as close as practical to the surface of the perforated band 114 on which the continuous elastic fibers 118 are collected. For example, this forming distance can be from about 2 inches to about 10 inches. inches Desirably, this distance is from about 2 inches to about 8 inches.

It may be desirable to have a perforated surface 114 that moves at a speed that is much greater than the initial velocity of the elastic fibers 118 in order to improve the alignment of the fibers 118 in essentially parallel rows and / or elongate the fibers 118 of so that they achieve a desired diameter. For example, the alignment of the elastomeric fibers 118 can be improved by having the perforated surface 114 moving at a speed of from about 2 to about 10 times greater than the initial velocity of the elastomeric fibers 118. The speed differences still older can be used if desired. Although different factors may affect the particular choice of speed for the perforated surface 114, this will typically be from about four to about eight times faster than the initial velocity of the elastomeric fibers 118.

Desirably, continuous elastomeric fibers are formed at a density per inch of material width that generally corresponds to the density of capillary vessels on the matrix face. For example, the density of filaments per inch of material width can vary from about 10 to about 120 such fibers per inch of material width. Typically, lower densities of the fibers (e.g., 10-35 fibers per inch in width) can be achieved with only one filament-forming matrix. Higher densities (eg, 35-120 fibers per inch width) can be achieved with multiple banks of a filament forming equipment.

The meltblown fiber component of the elastic fibrous fabric is formed using a conventional melt blowing device 124. The meltblowing device 124 generally extrudes a thermoplastic polymer resin through a plurality of small diameter capillary cups. meltblown as melted yarns inside a stream of heated gas (the primary air stream) which is generally flowing in the same direction as the extruded yarns of so that the extruded threads are attenuated, for example, cut or extended to reduce their diameter.

In the meltblown array 110, the position of the air plates which in conjunction with the matrix part define chambers and separations, can be adjusted in relation to the matrix part to increase or decrease the width of the air ducts. Attenuation gas such that the volume of attenuation gas passing through the air passages during a given period of time can be varied without varying the speed of the attenuation gas. Generally speaking, lower attenuation gas velocities and wider air duct separations are generally preferred if essentially continuous meltblown fibers or microfibers are to be produced.

The two streams of attenuation gas converge to form a gas stream which carries and attenuates the melted yarns, as they leave the holes, within the fibers depending on the degree of attenuation, of the microfibers, of a small diameter which it is usually smaller than the diameter of the holes. The fibers or microfibers carried by gas 126 are blown, by the action of the attenuation gas, on a collection arrangement which, in the embodiment illustrated in Figure 5 is the perforated endless band 114 which carries the elastomeric filament in a essentially parallel alignment. The fibers or microfibers 126 are collected as a coherent matrix of fibers on the surface of the elastomeric fibers 118 and of the perforated endless band 114, which is rotating from left to right as indicated by arrow 122 in Figure 5. If desired, blown fibers or microfibers with fusion 126 can be collected on the endless band drilled 114 to numerous hit angles. Vacuum boxes (not shown) can be used to assist in the retention of the matrix on the surface of the web 114. Typically the matrix tip 128 of the matrix 110 is at from about 6 inches to about 14 inches from the surface of the perforated band 114 on which the fibers are collected. The entangled fibers or microfibers 124 autogenously bond to at least a portion of the elastic continuous fibers 118 because the fibers or microfibers 124 are still somewhat tacky or melted while they are deposited on the elastic continuous fibers., thereby forming the elastic fibrous fabric 130. The fibers are cooled by allowing them to cool to a temperature below about 38 ° Celsius.

As discussed above, elastomeric fibers and elastomeric melt blown fibers can be deposited on a moving perforated surface. In one embodiment of the invention, meltblown fibers can be formed directly on top of the extruded elastomeric fibers. This is achieved by passing the fibers and the perforated surface under the equipment that produces blown fibers with fusion. Alternatively, a layer of blown fibers with elastomeric melts can be deposited on a perforated surface and the essentially parallel rows of elastomeric fibers can be formed directly on the elastomeric meltblown fibers. Various combinations of filament forming equipment and fiber former can be put into place to produce different types of elastic fibrous fabrics. For example, the elastic fibrous fabric may contain alternating layers of elastomeric fibers and elastomeric melt blown fibers. Various matrices for forming the meltblown fibers or creating the elastomeric fibers may also be arranged in a series to provide superposed layers of fibers.

Elastomeric meltblown fibers and elastomeric fibers can be made of any material that can be manufactured in such fibers, such as natural polymers or synthetic polymers. Generally, any suitable elastomeric fiber forming resins or mixtures containing the same can be used for the elastomeric melt blown fibers and any suitable elastomeric filament forming resins or mixtures containing the same can be used for the elastomeric fibers. The fibers can be formed from the same or from a different elastomeric resin.

For example, elastomeric melt blown fibers and / or elastomeric fibers can be made of block copolymers having the formula AB-A1 wherein A and A 'are each an ex-end block of thermoplastic polymer which can contain a styrenic moiety such as a poly (vinyl arene) and wherein B is a polymer block means such as a conjugated diene or a lower alkene polymer. The block copolymers can be, for example, (polystyrene / poly (ethylene-butylene) / polystyrene) block copolymers available from Shell Chemical Company under the trade designation KRATON R ™ G. One such block copolymer can be, for example, KRATON R ™ G-1657.

Other elastomeric materials which may be used include polyurethane elastomeric materials such as, for example, those available under the trademark ESTA E from B.F. Goodrich & Co., elastomeric polyamide materials such as, for example, those available under the trademark PEBAX from Rilsan Company, and elastomeric polyester materials such as, for example, those available under the trade designation Hytrel from E.I. DuPont De Nemours & Company The formation of elastomeric melt blown fibers of elastic polyester materials is described, for example, in United States of America Patent Number 4,741,949 issued to Morman, et al.

Useful elastomeric polymers also include, for example, elastic copolymers of ethylene and at least one vinyl monomer such as, for example, vinyl acetates, unsaturated aliphatic monocarboxylic acids, and esters of such monocarboxylic acids. The elastic copolymers and the formation of the elastomeric melt blown fibers of those elastic copolymers are described, for example, in United States of America Patent Number 4,803,117 issued to Daponte. Also, suitable elastomeric polymers are those prepared using metallocene catalysts such as those described in International Application WO 00/48834 to Smith, et al.

The processing aids can be added to the elastomeric polymer. For example, a polyolefin can be mixed with the elastomeric polymer (e.g., the elastomeric block copolymer A-B-A) to improve the processing of the composition. The polyolefin must be one which when mixed and subjected to an appropriate combination of high pressure and high temperature conditions, is extruded in a mixed form with the elastomeric polymer. Useful polyolefin mixing materials include, for example, polyethylene, polypropylene and polybutylene, including copolymers of ethylene, copolymers of propylene and copolymers of butylene. A particularly useful polyethylene can be obtained from U.S. I. Chemical Company under the trade designation Betrothing NA 601 (also referred to here as PE NA 601 or polyethylene NA 601). Two or more of the polyolefins can be used. Extruded blends of elastomeric polymers and polyolefins are described, for example, in US Pat. No. 4,663,220 issued to Wisneski, et al., Previously mentioned.

Elastomeric melt blown fibers and / or elastomeric fibers may have some tack and tack to improve autogenous bonding. For example, the elastomeric polymer itself can be tacky when formed into fibers or, optionally, a compatible tacky resin can be added to the extruded elastomeric compositions described above to provide the glutinized elastomeric fibers and / or the self-attaching fibers. With respect to sticky resins and sticky extrudable elastomeric compositions, note the resins and compositions as described in U.S. Patent No. 4,787,699, issued to Moulin.

Any glutinizing resin can be used which is compatible with the elastomeric polymer and can withstand the high processing (extrusion) temperatures. If the elastomeric polymer (eg, an elastomeric block copolymer A-B-A) is mixed with processing aids such as, for example, polyolefins or extension oils, the glutinizing resin must also be compatible with those processing aids. Generally, Hydrogenated hydrocarbon resins are preferred glutinizing resins due to their better temperature stability. The glutinizers of the REGALREZ ™ and ARKON ™ composite elastic material series are examples of hydrogenated hydrocarbon resins. The ZONATAK ™ 501 Lite is an example of a terpene hydrocarbon. REGALREZ ™ hydrocarbon resins are available from Hercules Incorporated. Resins of the ARKON ™ series are available from Arakawa Chemical (USA) Inc. The present invention is not limited to the use of these glutinizing resins, and other glutinizing resins which are compatible with other components of the composition and can withstand the high temperatures processing can also be used.

Typically, the mixture used to form the elastomeric fibers includes, for example, from about 40 to about 95 percent by weight of elastomeric polymer, from about 5 to about 40 percent polyolefin and from about 5 to about 40 percent resin glutinizer. For example, a particular useful composition including, by weight, about 61 to about 65 percent of KRAT0N ™ G-1657, about 17 to about 23 percent of polyethylene polymer, and about 15 to about 20 percent of REGALREZ ™ 1126 composite elastic material. Preferred polymers are metallocene-catalyzed polyethylene polymers such as, for example, Affinity® polymers, available from Dow® Chemical Company Affinity XUS59400.03L.

The elastomeric melt blown fiber component of the present invention can be a mixture of elastic and non-elastic particles or fibers. For example, such a mixture is described in U.S. Patent No. 4,209,563 issued to Sisson, wherein the elastomeric and non-elastomeric fibers are blended to form a single coherent fabric of randomly dispersed fibers. Another example of such elastic composite fabrics can be made by a technique described in U.S. Patent No. 4,741,949 issued to Morman et al. Previously cited. This patent discloses a nonwoven elastic material which includes a blend of meltblown thermoplastic fibers and other materials. The fibers and other materials are combined in the gas stream in which the meltblown fibers are carried so that intimate entangled mixing of the meltblown and other material fibers, for example, short fibers or pulp particles of wood, such as, for example, activated carbon, clays, starches or hydrocolloid particles (hydrogel) commonly referred to as super absorbent occurs prior to the collection of the fibers on a collecting device to form a coherent fabric of randomly dispersed fibers.

Once the bonded and stretched laminate is formed, such as according to the process shown in Figure 4, the material is cut into a desired shape and impregnated with the cleaning solution to form a wet cleaning cloth. For example, each wet cleaning cloth may generally be rectangular in shape and may have any suitable unfolded width and length. For example, the wet cleaning cloth may have an unfolded length of from about 2.0 to about 80.0 centimeters and desirably from about 10.0 to about 25.0 centimeters and an unfolded width of from about 2.0 to about 80.0 centimeters and desirably from about 10.0 to about 25.0 centimeters. Preferably, each individual wet cleaning cloth is arranged in a folded configuration and stacked one on top of the other to provide a stack of wet or interfolded wiping cloths in a configuration suitable for emergence assortment. Such bent configurations are well known to those skilled in the art and include the bent-c, doubled-z and bent-in configurations and the like. The stack of folded wet cleaning cloths can be placed in the interior of the container, such as a plastic tube, to provide a package of wet wiping cloths for eventual sale to the consumer. Alternatively, the wet wiping cloths may include a continuous strip of material which has perforations between each wiping cloth and which can be arranged in a pile or rolled up in a roll for the assortment.

The present invention can be better understood with respect to the following examples.

EXAMPLE NO. 1 To illustrate the properties of the product made in accordance with the present invention, tests were carried out on various samples of wet cleaning cloth materials in order to investigate the profiles of each. In this example, samples of 3 general types of materials are included. The first was a control group including a three layer laminate article with two coform outer layers and an elastomeric inner layer as described in the current application. The second, also described in the previous application, was a product similar to the first of the control group, but with a blown layer with added polypropylene melting of variable thickness on the exposed surfaces of the outer coform layers. The third type of sample was a non-woven composite cloth with a high content of pulp, available from Kimberly-Clark Corporation under the trademark Hydroknit (HK) The samples with the exposed layer blown with polypropylene fusion had a coating thickness of 4 grams per square meter, 6 grams per square meter, 8 grams per square meter, and 10 grams per square meter, resulting in a total of 6 groups of sample including the control and Hydroknit samples. Samples have been abbreviated: Control, HK, Coating 4 grams per square meter, Coating 6 grams per square meter, Coating 8 grams per square meter, and Coating 10 grams per square meter.

The Control and Coating samples were produced as described in the previous application and as shown in Figure 4. However, in the case of the control sample, the blowing bench with fusion 60 was not used. The weight The target base for each of the outer layers (coform + coating) was 26 grams per square meter, which resulted in an overall laminated basis weight of approximately 87 grams per square meter (see Table I for specific values) . In order to achieve a constant outer layer base weight, the flow rates for the meltblowing banks were altered so that by increasing the base coating weights, the coform bank flow rates were decreased and the rates were increased. coating bank flow.

The Hydroknit sample was produced by the method described in U.S. Patent No. 5,284,703 issued to Everhart, et al., And entitled "Non-woven Composite Fabric of High Pulp Content" which was incorporated herein by reference in its whole. The composite fabric contains more than about 70 percent, by weight, pulp fibers which are hydraulically entangled in a continuous filament substrate. The process comprises basically wet-laid pulp that is being added to a filament attached with spinning.

For each sample a roll was prepared and then cut into 8.5"x 8.5" sheets which were then bent according to a modified N-fold before wetting. The prepared sheets were then wetted with the humidifying solution, which was applied to the cleaning cloths using a stainless steel pipe with holes from which the solution was dropped on the cleaning cloths, resulting in a product similar to that available for consumers. The cleaning cloths were wetted with the solution at an aggregate level of 250% and placed in sealed ZIP-LOCK bags. The wet cleaning cloths were then subjected to a series of standardized tests. All tests were carried out with constant laboratory conditions of 23 ^ + 2 ° Celsius and 50 ^ 5% humidity unless declared otherwise. Table I below shows the most relevant physical data for each of the 6 samples, including: basis weight (gsm), volume (mm), absorption capacity (g / g), coefficient of friction (COF) in the direction of the machine (MD), cup crushing energy (g * mm), resistance to machine direction tension (MD) and resistance to machine direction (CD) tension.

The volume of the samples is a measure of the thickness. The volume is measured at 0.05 pounds per square inch of pressure with a Starret type volume tester, in units of millimeters (mm). The tester used a plate of 7.6 centimeters in diameter and care must be taken to ensure that the plate does not fall on a fold or wrinkle that may result from packing and / or bending.

The absorption capacity of paper products (either water or oil absorbing capacities) can be determined according to the following procedure. A pan large enough to contain water to a depth of at least 5.08 centimeters is filled with distilled water (or oil). A balance, such as the balance OHAUS GT480, is used in addition to a stopwatch. A cutting device, such as that sold under the trade designation TMI DGD by Testing Machines, Inc., of Amityville, New York, and a matrix with dimensions of 4 inches by 4 inches (0.01 inches) (10.16 centimeters by 10.16 centimeters +0.25 centimeters) was also used. The matrix size specimens are cut and weighed dry to the nearest 0.01 grams. A chronometer was started when the specimen is placed in the water (or oil) tray and soaked for 3 minutes + 5 seconds. At the end of the specified time, the specimen is removed by forceps and attached to a hanging bracket to hang in a "diamond" shaped position to ensure adequate fluid flow from the specimen In addition, the specimen is hung in a chamber that has 100 percent relative humidity for 3 minutes + 5 seconds. The specimen was then dropped on the weighing plate when the clamp was released. The weight is then recorded to the nearest 0.01 grams. The absorbent or absorptive capacity of each specimen is then calculated as follows: Absorbent Capacity (g) = Wet Weight (g) - Dry Weight (g) This gave an absorption capacity in grams for the sample which is frequently reported by sample weight, giving a specific absorption capacity with units of grams absorbed per gram of sample as reported in Table I.

The coefficient of friction can be measured with the known devices which drag a probe on the surface of a paper sample at a constant rate. The probe is modified to make a melted glass of 40-60 microns in diameter, lying flat, applying a normal force of 12.5 grams to the sample, and this is advanced on the tissue at a rate of one millimeter per second. The probe is advanced 5 centimeters in a first direction, providing data for a "forward" scan and then it is returned to move back to the starting point at the same speed, providing data for the "exploration" of Reverse. "The coefficient of friction can be calculated by dividing the frictional force by the normal force measured during the exploration (not taking into account the initial static resistance.) The frictional force is the lateral force on the probe during the exploration, an exit of the instrument After the first test comprising a forward and reverse exploration, the sample is rotated 180 degrees and placed again for the second test with another pair of forward and reverse scans along a new trajectory so that the forward exploration of the second test is the same direction as the reverse exploration in the first test.The coefficient of friction for the forward exploration of the second test and the reverse exploration in the first test are averaged for give the coefficient of friction in a first direction, and the coefficient of friction for the reverse exploration of the The second test and the forward scan in the first test are averaged to give the coefficient of friction in a second direction opposite to the first direction. This process is repeated for 10 samples to give averaged coefficients of friction for the two directions.

The softness of a non-woven fabric can be measured according to a "cup crush" test. The cup crush test evaluates fabric stiffness by measuring the peak load (also called the "cup crush load" or just "cup crush") required for a foot shaped hemispherically of 4.5 centimeters in diameter to crush a piece of 23 centimeters by 23 centimeters of fabric formed in an inverted cup of approximately 6.5 centimeters in diameter by 6.5 centimeters in height while the cup-shaped fabric is surrounded by a cylinder of approximately 6.5 centimeters in diameter to maintain a uniform deformation of the cup-shaped fabric. An average of 10 readings is used. The foot and cup are aligned to avoid contact between the cup walls and the foot which can affect the readings. The peak load is measured while the foot is descending at a rate of about 380 millimeters per minute and was measured in grams. The rate crush test also gave a value for the total energy required to crush a sample (cup crush energy) which is the energy from the start of the test to the peak load point, for example, the area under the curve formed by the load in grams on an axis and the distance that the foot moves in millimeters over the other. The cup crush energy is therefore reported in g * mm. Lower cup crush values indicate a softer laminate. A suitable device for measuring cup crushing is a load cell model FTD-G-500 (range of 500 grams) available from Schaevitz Company of Pennsauken, New Jersey.

The peak load voltage test is a measure of the breaking strength and elongation or tension of a fabric when subjected to unidirectional stress. This The test is known in the art and is similar to the test ASTM-1117-80 § 7, which uses a tension rate of 12 inches per minute. The results are expressed in grams at break and percentage of stretch before breaking. The upper numbers indicate a stronger and more stretchable fabric. The term "load" means the force or maximum load, expressed in units of weight, required to break the specimen in a stress test. The values for the tensile strength are obtained using a specified fabric width, a clamp width and a constant extension rate. The test is carried out using a wet product as it would be representative of a consumer use. The fabric test can be carried out in both the machine direction and the cross machine direction, which can be determined by one familiar with the non-woven materials by the orientation of the fibers. It is important that the samples be either parallel or perpendicular to the machine direction to ensure accuracy. The test is carried out using a clamp of 4 inches wide with a smooth face and a round horizontal rod of 0.25 inches comprising each clamp mechanism. The specimen is embraced in, for example, an Instron Model ™ apparatus, available from Instron Corporation of Canton, Massachusetts, or a Thwing Albert Model INTELLECT II available from the Thwing Albert Instrument Company of Philadelphia, Pennsylvania which has 3-inch parallel clamps. long. This fabric tension closely simulates conditions in actual use.

* The process problems experienced during the production of the 6 gsm coating cleaning cloths resulted in erroneous data for the sample, as most obviously indicated by the low basis weight. This production problem should be considered when evaluating any of the data in this sample.

An advantage provided by the meltblown surface layer is a reduction in lint production. In order to quantify this advantage, a wet wiping cloth lint test was carried out. Again 8.5"x 8.5" wet cleaning cloths were used. The test was carried out by placing a cleaning cloth of each of the sample groups in 5L or a larger container containing 2L of distilled water. The cleaning cloth was then swung in the left-to-right direction for 30 seconds. A sample of the resulting solution was then poured into a smaller flask. This solution was tested with respect to particles of varying sizes using a HIAC / ROYCO Automatic Bottle Sampling Apparatus (ABS-2) and a HIAC / ROYCO Model 8000A / 8000S Particle Counter, both available from Pacific Scientific Instruments of Grant Pass, OR. The number of lint particles of each sample was counted and separated by size. The results of the test are shown in Table II given below.

* See the note given aba or Ta I As shown above, the meltblown coating of the present invention significantly reduced lint levels compared to the control. In addition, the meltblown coating of 4 grams per square meter produced similar results when compared to the meltblowing coating of 10 grams per square meter.

When the lint tests were carried out as shown above, particle sizes of 50 microns or greater are perhaps of more concern since these particles are visible to the user. As shown, meltblown coatings made in accordance with the present invention can reduce lint levels by more than about 30%, such as more than about 40%, such as more than about 50%, such as more than about 60%, and, in one embodiment, they can reduce the lint levels by more than about 70%.

EXAMPLE NO. 2 To demonstrate the utility of the treated fabrics according to the present invention, a pilot meltblowing line was operated to provide a light melt blowing coating of Findley adhesive H-1296 made by Bostik Findley, Inc. (of Middleton, Massachusetts), which is believed to comprise ethylene vinyl acetate. The tests were carried out on a blown J & M fusion line made by J &M Laboratories, Inc. (of Dawsonville, Georgia). Meltblowing was applied on the non-creped (UCTAD) non-calendered tissue base sheet tissues made generally according to the teachings of US Pat. Nos. 5,672,248, issued to Wendt. , and others on 30 of September of 1997, and 5,607,551, granted to Farrington and others on March 4, 1997.

A first tissue base sheet UCTAD comprised a three layer fabric formed using a stratified headbox. The two outer layers each had a target basis weight of 8 grams per square meter (gsm) of an Alabama kraft hardwood bleached 100% with the binder added at a level of 5.1 kilograms per metric ton fiber. The binder was a PROSOFT® TQ1003 binder, an imidazoline binder (more specifically an oleylimidazolino binder) manufactured by Hercules Inc., (of Wilmington, Delaware) which inhibits hydrogen bonding, resulting in a weaker sheet. The inner layer of the base sheet contained slightly milled lightly kraft northern softwood fibers LL19 100% from Kimberly-Clark Corporation (of Houston, Texas) with the strength additive PAREZ® 631-NC made by Bayer AG (from Leverkusen , Germany), added at a level of 4 kilograms per metric ton of fibers.

The UCTAD base sheet was formed using 25% fast transfer and dried on a continuous textured drying fabric to impart a three dimensional pattern essentially the same as the pattern on the KLEENEX® COTTONELLE commercial toilet paper. The resulting base sheet had a total basis weight of 30 grams per square meter and a average geometric tensile strength of 750 grams per 3 inches. However, unlike a commercial toilet paper, the base sheet used in this example had a composition designed to provide problems of high soles and lint, particularly due to the composition of the outer layers. Prior to meltblowing treatment, the air side of the base sheet (the side that was not against the surface of the dryer continued during drying) was observed with respect to the release of dust or lint (typically fibers) hardwood) when rubbed. Given that the air side of a dried fabric in continuous form generally experiences less mechanical comparison during drying than what the side against the surface of the dryer continues to do, the air side can be less attached and more feasibly loose eschar or lint under frictional f erces.

The dry UCTAD fabric with the air side up was then placed on a moving carrier wire in the meltblowing line that carried the fabric at a rate of 81 feet per minute to pass under a blow mold with melting 1.5 inches above the fabric with a spray width of 12 inches. The hot melt tank was at 330 ° Fahrenheit, the die tip at 325 ° Fahrenheit, and the air temperature was 375 ° Fahrenheit. The hot melt pump operated at 15 grams per minute. The blown fibers with melting of the tip of The matrix was deposited on the tissue tissue, resulting in a light melting blow layer very tight to the tissue and a basis weight of about 2 grams per square meter on one side of the tissue.

After the treatment, low base weight meltblown fibers were not visible to the eye without help, but the treated side of the tissue that previously underwent dust and lint formation was much more resistant to lint. The fabric remained absorbent and had a soft and pleasant feel with a higher surface friction than the untreated side due to the presence of the meltblown fibers.

Additional tests were carried out at about 160 feet per minute, giving a meltblowing layer with a basis weight of about 1.1 grams per square meter.

The tests were carried out with a second UCTAD base sheet essentially the same as the first UCTAD base sheet, except that the outer layers contained 50% bleached eucalyptus kraft and 50% Alabama bleached kraft hardwood, still with others base coat weights of 8 grams per square meter and still having 5.1 kilograms / tonne of the present binder.

With the second UCTAD base sheet, the meltblowing tests were carried out at a rate of 81 feet per minute, 161 feet per minute and 320 feet per minute, giving the meltblowing layers on the air side of the base sheet with base weights of about 2 grams per square meter, about 1 gram per square meter, and about 0.5 grams per square meter, respectively.

In another trial, the base sheet was a base sheet of 40 grams per square meter of 100% bleached quimotermomechanical softwood from the north (BCTMP), made essentially according to Example 1 of the Patent of the United States of America Number 6,436,234 granted on August 20, 2000 to Chen, and others. The meltblowing line was operated at 120 feet per minute to apply about 1.5 grams of meltblowing to a first side of the base sheet. The treated base sheet was placed on a roller and then put on the front of the machine again, where it was unrolled with the untreated side to treat the second side of the left. Therefore, melt blowing was applied to both sides of the base sheet.

These and other modifications and variations of the present invention may be practiced by those of ordinary skill in the art without departing from the spirit and scope of the present invention, which is more particularly set forth in the appended claims. In addition, you must It is understood that the aspects of the various incorporations can be exchanged in whole or in part. In addition, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and that it is not intended to limit the invention so far described in such appended claims.

Claims (20)

1. A nonwoven material exhibiting reduced lites and eschars comprising: a non-woven fabric comprising pulp fibers, the non-woven fabric having a first side and a second side; Y meltblown fibers applied to the first side of the non-woven fabric, the meltblown fibers being distributed over the surface of the first side of the non-woven fabric, the meltblown fibers being present in an amount less than about 8 grams per square meter .

2. A tissue product exhibiting reduced lites and scabs comprising: a tissue of tissue comprising pulp fibers, the tissue of tissue having a first side and a second opposite side; Y meltblown fibers applied to the first side of the tissue tissue, the meltblown fibers being distributed over the surface of the first side of the tissue of tissue in a manner that reduces lint and eschar, blown fibers with melt being present in an amount of less than about 8 grams per square meter.

3. A damp cleaning cloth comprising: a stretched-together laminate comprising a first coform fabric, a second coform fabric and an elastic layer located between the first coform fabric and the second coform fabric, the first coform fabric defining a first side to the outside of the stretched-attached laminate and the second coform fabric defines a second outer side of the stretched-attached laminate; the meltblown fibers applied to the first outer side and the second outer side of the stretch-bound laminate, the meltblown fibers being distributed over the surfaces of the stretch-bonded laminate, the meltblown fibers being present on each side of the stretched laminate -united in an amount of less than about 8 grams per square meter; Y a cleaning solution impregnated in the stretched-attached laminate.

4. A nonwoven material, tissue product or cleaning cloth as claimed in any one of clauses 1 to 3, characterized in that the meltblown fibers are present in an amount of less than about 6 grams per square meter, preferably less than about 4 grams per square meter, preferably less than about 2 grams per square meter, and preferably less than about 1 gram per square meter.

5. A non-woven material as claimed in clause 1, characterized in that the non-woven fabric comprises a tissue of tissue.

6. A nonwoven material or tissue product as claimed in clauses 1 or 2, characterized in that the fabric has a basis weight of from about 10 grams per square meter to about 120 grams per square meter.

7. A nonwoven material, tissue product, or wet cleaning cloth as defined in any one of Clauses 1 to 3, characterized in that the meltblown fibers are made of a material selected from the group consisting of styrene-butadiene copolymers, polyvinyl acetate homopolymers, copolymers of ethylene vinyl acetate, ethylene vinyl alcohol, acrylic copolymers of vinyl acetate, copolymers of vinyl ethylene chloride, terpolymers of ethylene vinyl chloride-vinyl acetate, polymer of acrylic polyvinyl chloride, acrylic polymers, waxes , and mixtures thereof.

8. A nonwoven material or tissue product as claimed in clauses 1 or 2, characterized in that the fabric comprises a fabric dried through non-creped air, the fabric includes one side to the air and one side to the fabric.

9. A non-woven material or tissue product as claimed in clauses 1 or 2, characterized in that the meltblown fibers are applied to the first side and the second side of the fabric, the meltblown fibers being present on each side of the fabric. woven in an amount of less than about 6 grams per square meter.

10. A nonwoven material or tissue product as claimed in clauses 1 or 2, characterized in that the fabric is made of a stratified fiber supply, the fabric includes a middle layer placed between a first outer layer and a second outer layer .

11. A non-woven material, a tissue product or cleaning cloth as claimed in any one of Clauses 1 to 3, characterized in that the meltblown fibers comprise continuous filaments having a diameter of less than about 10 microns, preferably of less than about 5 microns.

12. A nonwoven material or tissue product as claimed in clauses 1 or 2, characterized in that the melt blown fibers are applied to the first side of the fabric in an amount sufficient to reduce the coefficient of friction of the first side of the fabric.

13. A nonwoven material or tissue product as claimed in clauses 1 or 2, characterized in that the meltblown fibers are applied to the first side of the fabric in an amount sufficient to reduce the eschar by at least 30%.

14. A non-woven material or tissue product as claimed in clauses 1 or 2, characterized in that the fabric contains an anchoring agent that joins with the meltblown fibers.

15. A non-woven material or tissue product as claimed in clause 14, characterized in that the anchoring agent comprises synthetic fibers present in the fabric in an amount of up to about 10% by weight, and wherein the tissue is formed of a stratified fiber supply containing an outer layer defining the first side of the fabric, the outer layer containing the synthetic fibers.

16. A non-woven material or tissue product as claimed in clauses 1 or 2, characterized in that the fabric comprises a coform fabric.

17. A cleaning cloth as claimed in clause 16, further characterized in that it comprises a cleaning solution impregnated in the cleaning cloth.

18. A nonwoven material, tissue product, or wet cleaning cloth as defined in any one of clauses 3, 16, or 17, characterized in that the coform fabric comprises polyolefin fibers and pulp fibers and wherein the blown fibers with melting they comprise polyolefin fibers.

19. A nonwoven material, tissue product, or wet cleaning cloth as claimed in any one of the preceding clauses, characterized in that it has a cup crush of less than about 120 grams per centimeter.

20. A cleaning cloth as claimed in clauses 3 or 17, characterized in that the melt blown fibers decrease the lint levels for particles greater than 50 microns by at least about 30%, preferably at least about 40 microns. %, and preferably at least about 50%. RESU IN Non-woven fabrics are described having reduced levels of lint and eschar. According to the present invention the non-woven fabrics are treated on at least one surface with a small amount of polymeric component. The polymer component may be present, for example in the form of meltblown fibers. The meltblown fibers are made of a polymer that is compatible with the non-woven fabric. By adding relatively small amounts of melt blown fibers to at least one side of the non-woven material, the lint and eschar levels have been found to be significantly reduced. The non-woven fabric can be any fabric containing pulp fibers, such as a tissue of tissue or a coform fabric.