US20040255440A1

US20040255440A1 - Three-dimensionally imaged personal wipe

Info

Publication number: US20040255440A1
Application number: US10/819,569
Authority: US
Inventors: Nick Carter; Jennifer Mayhorn
Original assignee: Polymer Group Inc
Current assignee: Avintiv Specialty Materials Inc
Priority date: 2003-04-11
Filing date: 2004-04-07
Publication date: 2004-12-23

Abstract

The present invention is directed to a hydroentangled nonwoven personal wipe, and more specifically to a hydroentangled three-dimensionally imaged personal wipe comprised of at least one raised portion and a background portion, wherein said personal wipe comprises a minimal amount of transverse apertures.

Description

TECHNICAL FIELD

The present invention relates to a nonwoven personal wipe, and more specifically to a hydroentangled three-dimensionally imaged personal wipe comprised of at least one raised portion and a background portion, wherein said personal wipe comprises transverse apertures with a minimal surface areas.

BACKGROUND OF THE INVENTION

The production of conventional textile fabrics is known to be a complex, multi-step process. The production of fabrics from staple fibers begins with the carding process whereby the fibers are opened and aligned into a feedstock referred to in the art as “sliver”. Several strands of sliver are then drawn multiple times on a drawing frames to; further align the fibers, blend, improve uniformity and reduce the sliver's diameter. The drawn sliver is then fed into a roving frame to produce roving by further reducing its diameter as well as imparting a slight false twist. The roving is then fed into the spinning frame where it is spun into yarn. The yarns are next placed onto a winder where they are transferred into larger packages. The yarn is then ready to be used to create a fabric.

For a woven fabric, the yarns are designated for specific use as warp or fill yarns. The fill yarns (which run on the y-axis and are known as picks) are taken straight to the loom for weaving. The warp yarns (which run on the x-axis and are known as ends) must be further processed. The large packages of yarns are placed onto a warper frame and are wound onto a section beam were they are aligned parallel to each other. The section beam is then fed into a slasher where a size is applied to the yarns to make them stiffer and more abrasion resistant, which is required to withstand the weaving process. The yarns are wound onto a loom beam as they exit the slasher, which is then mounted onto the back of the loom. The warp yarns are threaded through the needles of the loom, which raises and lowers the individual yarns as the filling yarns are interested perpendicular in an interlacing pattern thus weaving the yarns into a fabric. Once the fabric has been woven, it is necessary for it to go through a scouring process to remove the size from the warp yams before it can be dyed or finished. Currently, commercial high-speed looms operate at a speed of 1000 to 1500 picks per minute, where a pick is the insertion of the filling yam across the entire width of the fabric. Sheeting and bedding fabrics are typically counts of 80×80 to 200×200, being the ends per inch and picks per inch, respectively. The speed of weaving is determined by how quickly the filling yarns are interlaced into the warp yarns, therefore looms creating bedding fabrics are generally capable of production speeds of 5 inches to 18.75 inches per minute.

In contrast, the production of nonwoven fabrics from staple fibers is known to be more efficient than traditional textile processes, as the fabrics are produced directly from the carding process.

Nonwoven fabrics are suitable for use in a wide variety of applications where the efficiency with which the fabrics can be manufactured provides a significant economic advantage for these fabrics versus traditional textiles. However, nonwoven fabrics have commonly been disadvantaged when fabric properties are compared to conventional textiles, particularly in terms of resistance to elongation, in applications where both transverse and co-linear stresses are encountered. Hydroentangled fabrics have been developed with improved properties, by the formation of complex composite structures in order to provide a necessary level of fabric integrity. Subsequent to entanglement, fabric durability has been further enhanced by the application of binder compositions and/or by thermal stabilization of the entangled fibrous matrix.

More recently, hydroentanglement techniques have been developed which impart images or patterns to the entangled fabric by effecting hydroentanglement on three-dimensional image transfer devices. U.S. Pat. No. 5,674,591, hereby incorporated by reference, discloses a three-dimensionally imaged nonwoven fabric comprised of fibrous transition regions. Such fibrous transition regions are described as fiber bundles that affix the imaged or raised portion of the fabric to the planar background portion of the fabric. The formation of the fibrous transition regions create void spaces there between said regions, which ultimately allow for particulates to pass through the fabric.

Three-dimensional image transfer devices are disclosed in U.S. Pat. No. 5,098,764, which is also hereby incorporated by reference; with the use of such image transfer devices being desirable for providing a fabric with enhanced physical properties as well as an aesthetically pleasing appearance.

For personal wipe applications, it is desirable for a three-dimensionally imaged nonwoven fabric to exhibit a combination of specific physical characteristics. For example, when such fabrics are used in the formation of baby wipes, it is advantageous for the wipe to be durable and comprise a minimal amount of void spaces or holes, so as to prevent the penetration of particulates through the wipe, which may soil the user's hands. Further, the void spaces or holes formed between the fibrous transition regions of the aforementioned prior art, U.S. Pat. No. 5,674,591, compromise the overall strength of the wipe.

European Patent No. EP1032366B1, to Pung, et al. describes a personal cleansing wipe comprising fibrous transition regions, wherein the wipe has a series of void spaces as a result of the fiber bundles formed within the transition regions. Such void spaces are deleterious to the wipe, whereby particulates may easily pass through the wipe, soiling the user's hands. Further, the void spaces detract from the overall strength of the personal cleansing wipe.

Notwithstanding various attempts in the prior art to develop a hydroentangled three-dimensionally imaged nonwoven fabric acceptable for personal wipe applications, a need continues to exist for a nonwoven fabric which provides a three-dimensional image, as well as the durability and strength desirable in many end-use applications.

SUMMARY OF THE INVENTION

In accordance with the present invention, the three-dimensionally image nonwoven personal wipe is hydroentangled on a three-dimensional image transfer device, wherein the resulting fabric comprises a minimal amount of transverse apertures, preferably less than 50%. The apertures present within the wipe have a surface area in the range preferably between 0.05-0.25 mm ², more preferably between 0.05-0.20 mm², and most preferably between 0.05-0.15 mm². A minimal amount of transverse apertures within the imaged nonwoven fabric, in addition to the small surface area of those apertures present, provides a personal wipe with improved strength. Further, the wipe of the present invention provides better protection from the penetration of particulates through the wipe, which may soil the user's hands.

In one embodiment of the present invention, the basis weight and the density, respectively, of the raised portions are the same as the basis weight and density, respectively, of the background portion of the fabric. As used herein, the term “basis weight” is the weight of a unit area of fibrous web or portion thereof being characterized. As used herein, the term “density” is the weight of a unit volume of a fibrous web or portion thereof being characterized. Traditional embossing patterning processes produce regions of varying density.

In a second embodiment of the present invention, the basis weight of the raised portions is greater than the basis weight of the background portion and the density of the raised portions is the same as the density of the background portion.

In a third embodiment of the present invention, the basis weight of some of the raised portions are substantially the same as the basis weight of the background portion and the basis weight of other raised portions are greater than the basis weight of the background portion. In this embodiment, as in the other embodiments, the density of all of the raised portions is essentially the same as the density of the background portion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic view of an apparatus for manufacturing a nonwoven fabric, embodying the principles of the present invention.[0016]

DETAILED DESCRIPTION

While the present invention is susceptible of embodiment in various forms, there is shown in the drawings, and will hereinafter be described, a presently preferred embodiment of the invention, with the understanding that the present disclosure is to be considered as an exemplification of the invention, and is not intended to limit the invention to the specific embodiment illustrated. [0017]
Manufacture of a durable nonwoven personal wipe embodying the principles of the present invention is initiated by providing the fibrous matrix, which can include the use of staple length fibers, continuous filaments, and the blends of fibers and/or filaments having the same or different composition. Fibers and/or filaments are selected from natural or synthetic composition, of homogeneous or mixed fiber length. Suitable natural fibers include, but are not limited to, cotton, wood pulp and viscose rayon. Synthetic fibers, which may be blended in whole or part, include thermoplastic and thermoset polymers. Thermoplastic polymers suitable for blending with dispersant thermoplastic resins include polyolefins, polyamides and polyesters. The thermoplastic polymers may be further selected from homopolymers; copolymers, conjugates and other derivatives including those thermoplastic polymers having incorporated melt additives or surface-active agents. Staple lengths are selected in the range of 0.25 inch to 10 inches, the range of 1 to 3 inches being preferred and the fiber denier selected in the range of 1 to 22, the range of 1.2 to 6 denier being preferred for general applications. The profile of the fiber and/or filament is not a limitation to the applicability of the present invention. [0018]
The hydroentangled three-dimensionally imaged nonwoven personal wipe of the present invention comprises transverse apertures with a minimal surface area of preferably less than 0.15 mm[0019] ², more preferably less than 0.10 mm², and most preferably less than 0.05 mm². Transverse apertures are those that extend completely through the fabric.
With reference to FIG. 1, therein is illustrated an apparatus for practicing the present method for forming a nonwoven fabric. The fabric is formed from a fibrous matrix, which typically comprises staple length fibers, but may comprise substantially continuous filaments. The fibrous matrix is preferably carded and cross-lapped to form a fibrous batt, designated F. In a current embodiment, the fibrous batt comprises 100% cross-lap fibers, that is, all of the fibers of the web have been formed by cross-lapping a carded web so that the fibers are oriented at an angle relative to the machine direction of the resultant web. U.S. Pat. No. 5,475,903, hereby incorporated by reference, illustrates a web drafting apparatus. [0020]
FIG. 1 illustrates a hydroentangling apparatus for forming nonwoven fabrics in accordance with the present invention. The apparatus includes a foraminous-forming surface in the form of [0021] belt 10 upon which the precursor web P is positioned for pre-entangling by entangling manifold 12. Pre-entangling of the precursor web, prior to three-dimensional imaging, is subsequently effected by movement of the web P sequentially over a drum 14 having a foraminous-forming surface, with entangling manifold 16 effecting entanglement of the web. Further entanglement of the web is effected on the foraminous forming surface of a drum 18 by entanglement manifold 20, with the web subsequently passed over successive foraminous drums 20, for successive entangling treatment by entangling manifolds 24, 24′.
The entangling apparatus of FIG. 1 further includes a three-[0022] dimensional imaging drum 24 comprising a three-dimensional image transfer device for effecting imaging of the now-entangled precursor web. The image transfer device includes a moveable foraminous imaging surface which moves relative to a plurality of entangling manifolds 26 which act in cooperation with three-dimensional elements defined by the surface asperities of the image transfer device to effect imaging and patterning of the fabric being formed.
It is within the purview of the present invention that a scrim be interposed in the formation of the precursor nonwoven web. The purpose of the scrim is to reduce the extensibility of the resultant three-dimensional imaged nonwoven fabric, thus reducing the possibility of three-dimensional image distortion and further enhancing fabric durability. Suitable scrims include unidirectional monofilament, bi-directional monofilament, expanded films, and thermoplastic spunbond. [0023]
The fabric of the present invention may be that of a laminate structure, wherein the precursor nonwoven web may combined with one or more additional fabric layers. Such layers include, but are not limited to, elastomeric fabrics, spunmelt fabrics, additional carded webs, and various films. In general, spunmelt fabrics include the formation of continuous, as well as discontinuous filament nonwoven fabrics. Nonwoven fabrics comprised of continuous filament formation involve the practice of the spunbond process. A spunbond process involves supplying a molten polymer, which is then extruded under pressure through a large number of orifices in a plate known as a spinneret or die. The resulting continuous filaments are quenched and drawn by any of a number of methods, such as slot draw systems, attenuator guns, or Godet rolls. The continuous filaments are collected as a loose web upon a moving foraminous surface, such as a wire mesh conveyor belt. When more than one spinneret is used in line for the purpose of forming a multi-layered fabric, the subsequent webs is collected upon the uppermost surface of the previously formed web. The web is then at least temporarily consolidated, usually by means involving heat and pressure, such as by thermal point bonding. Using this means, the web or layers of webs are passed between two hot metal rolls, one of which has an embossed pattern to impart and achieve the desired degree of point bonding, usually on the order of 10 to 40 percent of the overall surface area being so bonded. [0024]
A related means to the spunbond process for forming a layer of a nonwoven fabric is the melt blown process. Again, a molten polymer is extruded under pressure through orifices in a spinneret or die. High velocity air impinges upon and entrains the filaments as they exit the die. The energy of this step is such that the formed filaments are greatly reduced in diameter and are fractured so that microfibers of finite length are produced. This differs from the spunbond process whereby the continuity of the filaments is preserved. The process to form either a single layer or a multiple-layer fabric is continuous, that is, the process steps are uninterrupted from extrusion of the filaments to form the first layer until the bonded web is wound into a roll. Methods for producing these types of fabrics are described in U.S. Pat. No. 4,041,203, incorporated herein by reference [0025]
Additionally, suitable nano-denier continuous filament layers can be formed by either direct spinning of nano-denier filaments or by formation of a multi-component filament that is divided into nano-denier filaments prior to deposition on a substrate layer. U.S. Pat. Nos. 5,678,379 and 6,114,017, both incorporated herein by reference, exemplify direct spinning processes practicable in support of the present invention. U.S. Pat. Nos. 5,678,379 and 6,114,017, both incorporated herein by reference, exemplify direct spinning processes practicable in support of the present invention. [0026]
The present invention may include a reticulated film, microporous film, or monolithic film. A suitable process for forming a reticulated film is by utilization of the Reticulon Technology, as described in U.S. Pat. No. 4,381,326 to Kelly, hereby incorporated by reference. A suitable microporous film layer can include materials such as those reported in U.S. Pat. No. 5,910,225 herein incorporated by reference, in which pore-nucleating agents are used to form the micropores. Monolithic films as reported in U.S. Pat. No. 6,191,221, herein incorporated by reference, can also be utilized as a suitable film laminate means. [0027]
It is also within the purview of the present invention that a binder material can be either incorporated as a fusible fiber in the formation of the precursor nonwoven web or as a liquid fiber adhesive applied after imaged fabric formation. The binder material will further improve the durability of the resultant imaged nonwoven fabric during use. [0028]
A fabric made in accordance of the present invention is suitable for various personal wipe end-use applications, including, but not limited to hand held disposable baby wipes. It has been contemplated that the three-dimensionally imaged personal wipe can be further treated with one or more performance or aesthetic modifying composition to further alter the fabric structure or to meet end-use article requirements. [0029]
In a first embodiment of the present invention, the basis weight and the density, respectively, of the raised portions are the same as the basis weight and density, respectively, of the background portion of the fabric. [0030]
In a second embodiment of the present invention, the basis weight of the raised portions is greater than the basis weight of the background portion and the density of the raised portions is the same as the density of the background portion. [0031]
In a third embodiment of the present invention, the basis weight of some of the raised portions are substantially the same as the basis weight of the background portion and the basis weight of other raised portions are greater than the basis weight of the background portion. In this embodiment, as in the other embodiments, the density of all of the raised portions is essentially the same as the density of the background portion. [0032]
Depending on the desired end-use application, a variety of liquid cleansing compositions may be impregnated into or topically applied to the three-dimensionally imaged personal wipe. For example, a wide variety of cleansing surfactants are useful herein and include those selected from the group consisting of anionic surfactants, nonionic surfactants, amphoteric surfactants, cationic surfactants, and mixtures thereof. Further, the fabric may incorporate an aqueous cleansing composition that optionally and preferably comprise a lipophilic skin conditioning agent which is useful for providing a conditioning benefit to the skin during the use of the product. [0033]
Additionally, the three-dimensionally imaged fabric of the present invention can also optionally comprise a safe and effective amount of one or more active ingredients or pharmaceutically-acceptable salts thereof. [0034]
The term “safe and effective amount” as used herein, means an amount of an active ingredient high enough to modify the condition to be treated or to deliver the desired skin benefit, but low enough to avoid serious side effects, at a reasonable benefit to risk ratio within the scope of sound medical judgment. What is a safe and effective amount of the active ingredient will vary with the specific active, the ability of the active to penetrate through the skin, the age, health condition, and skin condition of the user, and other like factors. [0035]
The active ingredients useful herein can be categorized by their therapeutic benefit or their postulated mode of action. However, it is to be understood that the active ingredients useful herein can in some instances provide more than one therapeutic benefit or operate via more than one mode of action. Therefore, classifications herein are made for the sake of convenience and are not intended to limit the active ingredient to that particular application or applications listed. [0036]
The cleansing agent may be incorporated by any method suitable for the application, including flood coating, spray coating or metered dosing, can be used to impregnate the substrates herein with the emulsion composition described herein. More specialized techniques, such as Meyer Rod, floating knife or doctor blade, which are typically used to impregnate cleansing solutions into absorbent sheets may also be used. [0037]
The cleansing solution should preferably comprise from about 100% to about 400%, preferably from about 200% to about 400% by weight of the absorbent sheet. [0038]
Prior to or after impregnation of the liquid cleansing solution into the substrate, the substrate may be folded into stacks. The substrate is then typically packaged in any of the moisture and vapor impermeable packages known in the art. [0039]
From the foregoing, it will be observed that numerous modifications and variations can be affected without departing from the true spirit and scope of the novel concept of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated herein is intended or should be inferred. The disclosure is intended to cover, by the appended claims, all such modifications as fall within the scope of the claims. [0040]

Claims

What is claimed is:

1. A method of making a three-dimensionally imaged personal wipe comprising the steps of:

a. providing a precursor web;

b. providing a three-dimensional image transfer device, wherein said three-dimensional image transfer device is a foraminous surface comprising a plurality of surface asperities; and

c. hydroentangling said precursor web on said three-dimensional image transfer device so as to impart a three-dimensional pattern into the resultant personal wipe comprising transverse apertures; said personal wipe comprised of a background portion and at least one raised portion, wherein said apertures have a surface area less than 0.15 mm².

2. A method of making a three-dimensionally imaged personal wipe as in claim 1, wherein said precursor web is comprised of staple length fibers.

3. A method of making a three-dimensionally imaged personal wipe as in claim 2, wherein said staple length fibers are selected from the group consisting of natural fiber, synthetic fibers, and the combination thereof.

4. A method of making a three-dimensionally imaged personal wipe as in claim 3, wherein said natural fibers are selected from the group consisting of cotton, wood pulp, viscose rayon, and the combination thereof.

5. A method of making a three-dimensionally imaged personal wipe as in claim 3, wherein said synthetic fibers are selected from the group consisting of polyolefins, polyamides, polyesters, and the combination thereof.

6. A method of making a three-dimensionally imaged personal wipe as in claim 1, wherein said raised portion is the same basis weight and density as said background portion.

7. A method of making a three-dimensionally imaged personal wipe as in claim 1, wherein said raised portion has a basis weight greater than said background portion basis weight and the density of said raised portion is the same as the density of said background portion.

8. A method of making a three-dimensionally imaged personal wipe as in claim 1, wherein at least one of said raised portions is the same as the basis weight of said background portion and the density of said raised portions are essentially the same as the density of said background portion.

9. A method of making a three-dimensionally imaged personal wipe as in claim 1, wherein said three-dimensionally imaged nonwoven fabric is a hard surface wipe.

8. A three-dimensionally imaged personal wipe comprising a precursor web that is hydroentangled on a three-dimensional image transfer device so as to impart a three-dimensional pattern into the resultant personal wipe comprising transverse apertures in an amount less than 50%; said personal wipe comprised of a background portion and at least one raised portion, wherein said apertures have a surface area in a range between 0.05-0.25 mm^2.

9. A method of making a three-dimensionally imaged personal wipe comprising:

a. three-dimensional imaged nonwoven fabric comprising transverse apertures; said nonwoven fabric comprised of a background portion and at least one raised portion, wherein said apertures have a surface area less than 015 mm²; and

b. an aqueous liquid cleansing composition comprising an effective amount of a cleansing surfactant, said aqueous liquid cleansing composition being coated onto or impregnated into said substrate to the extent from 100% to 400% by weight of the substrate.