WO1998002608A1 - Composites non-tisses entremeles par procede hydrique - Google Patents

Composites non-tisses entremeles par procede hydrique Download PDF

Info

Publication number
WO1998002608A1
WO1998002608A1 PCT/US1996/011653 US9611653W WO9802608A1 WO 1998002608 A1 WO1998002608 A1 WO 1998002608A1 US 9611653 W US9611653 W US 9611653W WO 9802608 A1 WO9802608 A1 WO 9802608A1
Authority
WO
WIPO (PCT)
Prior art keywords
fibers
composite
absorbent
matrix
fluid
Prior art date
Application number
PCT/US1996/011653
Other languages
English (en)
Inventor
Debra Nell Welchel
Eric Scott Kepner
Crystal Sutphin Leach
Original Assignee
Kimberly-Clark Worldwide, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kimberly-Clark Worldwide, Inc. filed Critical Kimberly-Clark Worldwide, Inc.
Priority to PCT/US1996/011653 priority Critical patent/WO1998002608A1/fr
Priority to AU64574/96A priority patent/AU6457496A/en
Publication of WO1998002608A1 publication Critical patent/WO1998002608A1/fr

Links

Classifications

    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
    • D04H1/44—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties the fleeces or layers being consolidated by mechanical means, e.g. by rolling
    • D04H1/46—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties the fleeces or layers being consolidated by mechanical means, e.g. by rolling by needling or like operations to cause entanglement of fibres
    • D04H1/498—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties the fleeces or layers being consolidated by mechanical means, e.g. by rolling by needling or like operations to cause entanglement of fibres entanglement of layered webs
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
    • D04H1/54—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by welding together the fibres, e.g. by partially melting or dissolving
    • D04H1/541—Composite fibres, e.g. sheath-core, sea-island or side-by-side; Mixed fibres
    • D04H1/5414—Composite fibres, e.g. sheath-core, sea-island or side-by-side; Mixed fibres side-by-side
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
    • D04H1/42—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
    • D04H1/425—Cellulose series
    • D04H1/4258—Regenerated cellulose series
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
    • D04H1/42—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties characterised by the use of certain kinds of fibres insofar as this use has no preponderant influence on the consolidation of the fleece
    • D04H1/4326—Condensation or reaction polymers
    • D04H1/435—Polyesters
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
    • D04H1/44—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties the fleeces or layers being consolidated by mechanical means, e.g. by rolling
    • D04H1/46—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties the fleeces or layers being consolidated by mechanical means, e.g. by rolling by needling or like operations to cause entanglement of fibres
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
    • D04H1/54—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by welding together the fibres, e.g. by partially melting or dissolving
    • D04H1/541—Composite fibres, e.g. sheath-core, sea-island or side-by-side; Mixed fibres
    • D04H1/5412—Composite fibres, e.g. sheath-core, sea-island or side-by-side; Mixed fibres sheath-core
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
    • D04H1/54—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by welding together the fibres, e.g. by partially melting or dissolving
    • D04H1/541—Composite fibres, e.g. sheath-core, sea-island or side-by-side; Mixed fibres
    • D04H1/5418—Mixed fibres, e.g. at least two chemically different fibres or fibre blends
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
    • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
    • D04H1/54—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by welding together the fibres, e.g. by partially melting or dissolving
    • D04H1/542—Adhesive fibres
    • D04H1/55—Polyesters
    • D—TEXTILES; PAPER
    • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
    • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
    • D04H13/00—Other non-woven fabrics

Definitions

  • the present invention is directed to entangled fibrous nonwoven webs. More particularly, the present invention is directed to hydroe ⁇ tangled structures which utilize absorbent fibers such as pulp fibers on one surface of the structures and matrix fibers such as polyolefin staple fibers on the other surface of the structures.
  • absorbent fibers such as pulp fibers on one surface of the structures
  • matrix fibers such as polyolefin staple fibers on the other surface of the structures.
  • the resultant composites have a wide variety of uses not the least of which is as a fluid management component in personal care absorbent articles such as diapers, training pants, incontinence garments, feminine hygiene products, bandages, wipes and the like.
  • Fibrous nonwoven structures are used in a wide variety of applications, including but not limited to absorbent structures.
  • absorbent structures include personal care absorbent articles which are used to absorb such body fluids as urine and menses.
  • personal care absorbent articles As personal care absorbent articles have advanced in design, they have become increasingly more complex both in the number of components they contain and the very specific functions that they perform. Originally most if not all of these products were quite simple in design. Typically they included some type of body side liner, a simple absorbent core composed of wood pulp fluff and a garment side backing sheet or barrier such as a layer of plastic film. Many of these products were quite bulky due to what is now known to be their ineffective structural designs. Poor functional ability was often compensated for simply by enlarging the products such as by adding more absorbent. Very little was known about each of the components, their advantages, limitations and how they interacted with one another.
  • Diapers and feminine hygiene products such as sanitary napkins are but two examples of where a reduction in thickness has been a driving force in design criteria.
  • Feminine hygiene products such as pantiliners are, in a relative sense, new products which have been made possible by the ability to reduce the size of the overall product. In so doing, maximum utilization of each and every component has become essential in the design of these products.
  • the present invention is directed to such endeavors. With respect to the ability of personal care absorbent articles to manage fluid intake and storage, low density fiuid intake materials such as through air bonded carded webs have shown excellent uptake and temporary reservoir functions.
  • a retention component to the structure creates a mixture of intake and retention functions and properties. While this can be an effective structure, in some instances it is desirable to separate functions to maximize performance in a personal care product. For instance, if the lofty structure is intended as a body side liner, then the addition of cellulose may increase the amount of flowback from the liner onto the user ' s skin. This is clearly not a desired function and therefore should be avoided.
  • Another alternative is to layer or ply the retention material with the fluid intake layer.
  • the layers can be held together through any number of attachment means, including adhesive bonds and thermal bonds. Thermal bonding requires a thermoplastic component in each layer. Consequently, a substrate which is made entirely from cellulose will not be thermally bo ⁇ dable. Adhesive bonding can be used to attach the layers, but adhesives can impede the creation of fluid pathways between the intake and retention surfaces.
  • the present invention is directed to a fibrous nonwoven composite which is formed from at least two fibers sources which are subsequently entangled with one another such as, for example, by hydroenta ⁇ gling.
  • One source of fibers used in the composites of the present invention is absorbent fibers such as wood pulp fibers which are capable of absorbing fluids such as urine and menses. Other absorbent fibers are also contemplated to be within the scope of the present invention.
  • the other source of fibers is fibers which are collectively referred to as matrix fibers. They are often less absorptive than the pulp fibers as their function is to take in fluids, temporarily hold them and then transfer them to the absorbent fibers.
  • matrix fibers include, but are not limited to, hydrophilic fibers and hydrophobic fibers which if desired may be treated to be hydrophilic.
  • the matrix fibers are typically staple or continuous fibers made from extrudable and spi ⁇ able polymers such as for example, rayon, polyolefins and polyesters.
  • the matrix fibers may include several types of fibers such as blends of poiyolefin fibers and polyester fibers.
  • the entangied composite To form the entangied composite, separate webs of absorbent and matrix fibers are formed, brought together and then entangled with one another. The degree of entanglement is controlled so as to prevent complete integration of the fibers from the two webs.
  • one side of the composite is essentially absorbent fibers while the other side of the composite is essentially matrix fibers.
  • the matrix fibers are selected so as to permit rapid intake of fluids such as urine and menses while the absorbent fibers serve to absorb and retain the fluids taken in by the matrix fibers.
  • the matrix fibers create a bodyfacing fluid intake exterior surface to the composite which is suitable for positioning toward or in contact with the wearer ' s body.
  • the fluid retention exterior surface, of the composite is essentially absorbent fibers, maximum absorption and retention is provided by this side of the product.
  • the absorbent fibers mix with the matrix fibers thereby creating a fluid transfer zone which, due to the entangiing, maximizes the transfer of fluid from the matrix fibers into the absorbent fibers.
  • there is no adhesive used there is believed to be less interference at the interface.
  • the composite so formed has particular utility as an absorbent mechanism for personal care absorbent articles such as diapers, training pants, incontinence devices, feminine hygiene products, wipers, bandages and the like.
  • the material of the present invention is particularly well-suited as a pantiliner material.
  • a material can be developed which has a soft exterior side suitable for use against the skin and an opposite surface which readily retains liquid.
  • the composite can be used underneath a conventional body side liner material to form yet another version of a finished product.
  • the entangied nonwoven composites according to the present invention should include from about 20 to about 75 percent by weight absorbent fibers and from about 25 to about 80 percent by weight matrix fibers based upon the total weight of the composite and in more refined embodiments can include from about 50 to about 60 percent absorbent fibers and about 40 to about 50 percent matrix fibers.
  • the fluid intake exterior surface should comprise essentially matrix fibers, the interior portion should contain a mixture of the absorbent fibers and matrix fibers entangled with one another and the fluid retention exterior surface snould contain essentially absorbent fibers. If desired, the absorbent fibers may contain a wet strength and/or a superabsorbent admixed therewith.
  • the resultant composite should have a fluid intake rate of about 2 cubic centimeters per minute or greater, a cohesion value of about 1.5 kilograms or greater, a cup crush value of about 1000 grams or less and a demand absorbency rate of one gram per minute or greater.
  • Variations to the composite may also be employed as, for example, by adding an additional layer to the composite such as a second top sheet positioned adjacent to and in contact with the fluid intake exterior surface of the top sheet.
  • This second top sheet may comprise a fibrous nonwoven web which itself may include a plurality of matrix fibers.
  • the composites of the present invention may be used in a wide variety of applications including, but not limited to, personal care absorbent articles such as, for example, pantiliners.
  • the design of such articles will include at a minimum, a backing sheet and an absorbent core.
  • the composites of the of the present invention may be used as the absorbent core in which case the fluid retention exterior surface of the composite will be positioned toward the backing sheet. As result, the fluid intake exterior surface can be positioned adjacent the wearer's skin.
  • the composite includes a second top sheet, the second top sheet will be positioned adjacent the wearer ' s skin.
  • Figure 1 is a cross-sectionai side view of an entangled absorbent and matrix fiber composite according to the present invention.
  • Figure 2 is a cross-sectional side view of another entangled absorbent and matrix fiber composite according to the present invention.
  • the top portion of the composite is a two layer material which provides dual functionality.
  • Figure 3 is a schematic side view of a process for forming an entangled absorbent and matrix fiber composite according to the present invention.
  • the equipment in this figure includes a hydroentangling apparatus.
  • Figure 4 is a top plan view of a test apparatus for measuring the rate at which an absorbent structure absorbs liquid.
  • Figure 5 is a cross-sectionai view of a test apparatus for measuring the rate at which an absorbent structure absorbs liquid.
  • Figure 6 is a side perspective view of a test apparatus for measuring demand absorbency of liquids by an absorbent structure.
  • Figure 7 is a photomicrograph of the material according to the present invention as described in Example 2a.
  • Figure 8 is a photomicrograph of the material according to the present invention as described in Example 3a.
  • Figure 9 is a photomicrograph of a material according to the present invention.
  • Figure 10 is a cut-away perspective view of a personal care absorbent article, in this case a pantiliner, employing a composite according to the present invention.
  • FIG. 1 there is shown in cross-section, an entangled absorbent fiber and matrix fiber composite according to the present invention.
  • the composite 100 is formed from two layers of material including a top sheet 102 and a bottom sheet 104.
  • the top sheet 102 is formed from a fibrous nonwoven web made from or including matrix fibers and the bottom sheet 104 is formed from a layer of absorbent fibers.
  • absorbent fibers is meant to include both natural and synthetic cellulosic and cellulose derivative fibers. Examples of such fibers include, but are not limited to, wood pulp fibers, rayon fibers, flax fibers, eucalyptus fibers, cotton fibers and the like.
  • absorbent fibers and “pulp fibers” shall be used interchangeably and shall have the same meaning and scope.
  • the two layers are positioned one on top of the other and then entangied together via a process such as is shown in Figure 3 and described below. In this process the absorbent fibers are integrated into the matrix fibers through the use of water jets. Due to the entangling of the absorbent fibers with the matrix fibers at the interface between the two sheets, the composite has three variable regions 106, 108 and 110 as shown in Figure 1.
  • the first exterior region 106 includes a fluid intake exterior surface 107 and it, aio ⁇ g with the first exterior region as a whole, are composed essentially of the fibers from the matrix layer or top sheet 102.
  • the weight percent of the matrix fibers, based upon the total weight of the fibers in region 106 will be greater than or equal to about 90 percent.
  • the second exterior region 110 includes a fluid retention exterior surface 111 and it, along with the second exterior region 110 as a whole, are composed essentially of the absorbent fibers from the absorbent sheet 104.
  • the weight percent of the absorbent fibers, based upon the total weight of the fibers in region 110 will be greater than or equal to about 90 percent.
  • the size of the regions 106, 108 and 110 depend on the degree of hydroentangling. As hydroentangling increases, region 108 wiil increase and regions 106 and 110 will decrease. As a result of the entanglement, the composite will include from about 20 to about 75 percent by weight absorbent fibers and from about 25 to about 80 percent by weight matrix fibers based upon the total weight of the composite 100. In certain, more refined embodiments, the composite 100 will include from about 50 to about 60 percent absorbent fibers and about 40 to about 50 percent matrix fibers based upon the total weight of the composite.
  • the first exterior region 106 serves as a fluid intake region while the interior region 108 serves as a fluid transfer region and the second exterior region 110 serves as a fluid retention region.
  • a personal care absorbent article such as a pantiliner
  • body fluids such as blood and menses will enter the fluid intake region 106 through the fluid intake exterior surface 107.
  • This surface and region are comprised of the matrix fibers which are less hydrophilic than the absorbent fibers.
  • the fluid wiil want to quickly pass through to another region in the material which, in this case, is the fluid transfer region 108. In this region there is a mixture of matrix fibers and absorbent fibers.
  • this region will have a higher affinity for absorbed fluids but not the affinity of the absorbent-rich fluid retention region 110. This in turn creates a driving force for the fluid.
  • the fluid is pulled into this region by the absorbent fibers but the matrix fibers keep the absorbent fibers somewhat apart which still gives the structure in this area a more open structure.
  • the high concentration of absorbent fibers in the fluid retention region 110 act to draw the fluid in so that the fluid can be stored away from the user.
  • the composite 100 is formed from three layers of material including the same top sheet 102 and a bottom sheet 104 as in Figure 1 and a second top sheet 105 disposed on a side 107 of the top sheet 102 which is opposed to the bottom sheet 104.
  • the top sheet 102 is formed from a layer of matrix fibers
  • the bottom sheet 104 is formed from a layer of absorbent fibers
  • the second top sheet 105 is formed from a fibrous nonwoven web which may include matrix fibers.
  • An advantageous embodiment is where the top sheet 102 and the second top sheet 105 contain bicompo ⁇ e ⁇ t matrix fibers so that they can be subjected to a heating process to bond the two sheets together.
  • region 106 will contain essentially matrix fibers.
  • Region 108 will be a mixture of absorbent fibers and nonwoven matrix fibers and region 110 will contain essentially absorbent fibers.
  • region 114 formed by the second top sheet 105 which wiil also contain essentially matrix fibers. These matrix fibers may be the same as or different than the matrix fibers in region 106 or they may be a blend of matrix fibers.
  • the second top sheet 105 can be designed to be aesthetically more pleasing to the touch and therefore more comfortable to the user. This can be accomplished by forming the second top sheet 105 from fibers which have a smaller diameter and/or denier than the fibers of the top sheet 102.
  • a dilute suspension of absorbent fibers in this case wood pulp fibers
  • a head-box 12 is supplied by a head-box 12 and deposited via a sluice 14 in a uniform dispersion onto a forming surface 16 of a conventional paper making machine.
  • the suspension of pulp fibers may be diluted to any consistency which is typically used in conventional paper making processes.
  • the suspension may contain from about 0.05 to about 0.5 percent by weight pulp fibers suspended in water to form a slurry.
  • a chemical debonder may be added to the slurry to further facilitate the process.
  • the slurry is laid down on the forming surface 16 and a vacuum assist 17 is used to pull the water out of the deposited fibers thereby creating a pulp sheet 18.
  • the pulp fibers may be any high-average fiber length pulp, low- average fiber length pulp or mixtures of the two types of fibers.
  • the high-average fiber length pulp fibers wiil typically have average fiber lengths from about 1.5 millimeters (mm) to about 6 millimeters.
  • Exemplary high-average fiber length wood pulp fibers include those available from the Kimberly-Clark Corporation under the trade designations Longlac 19, Coosa River 54 and Coosa River 56.
  • the low-average fiber length pulp fibers may be, for example, certain virgin hardwood pulps and secondary pulps (recycled) from sources such as, for example, newsprint, reclaimed paperboard and office waste.
  • the low-average fiber length pulp fibers typically have an average fiber length of less than about 1.2 mm and more typically in the range of about 0.7 to about 1.2 mm.
  • An exemplary low-average fiber length fiber is available from Kimberiy-Clark Corporation under the trade designation Coosa River 57.
  • Mixtures of high-average and low-average fiber length pulp fibers may contain varying proportions of the two types of fibers. Generally they can contain from about 20 to about 100 percent high-average length fibers and from about 0 to about 80 percent low-average length fibers on a weight percent basis based upon the total weight of all the fibers. It is also possible to use all of just one type of fiber although this would make processing more difficult as with, for example, 100 percent low-average length fibers.
  • the pulp fibers used in conjunction with the present invention may be unrefine ⁇ or may be beaten to varying degrees of refinement. Small amounts of wet-strength resins and/or resin binders may be added to improve strength and abrasion resistance.
  • Useful binders and wet- strength resins include, but are not limited to, Kymene 557 H resin available from the Hercules Chemical Company and Parez 631 resin which is available from American Cya ⁇ amid, Inc. Cross-linking agents and/or hydrating agents may also be added to the pulp mixture to reduce the degree of hydrogen bonding if a very open or loose nonwoven pulp fiber web is desired.
  • One exemplary debonding agent is available from the Quaker Chemical Company of Conshohocken, Pennsylvania under the trade designation Quaker 2008.
  • Another debonding agent is available from Witco/Sherex Chemical Company, Inc. of Dublin, Ohio under the trade designation Arosurf PA727.
  • debonding agents in an amount of, for example, about 1 to about 4 percent by weight of the pulp sheet appears to reduce the measured static and dynamic coefficients of friction and improves the abrasion resistance of the non-pulp side of the composite fabric.
  • the debonding agent is believed to act as a lubricant or friction reducer.
  • a fibrous nonwoven web substrate 20 is unwound from a supply roll 22 and travels in the direction indicated by the arrow associated therewith.
  • the nonwoven substrate 20 optionally may be passed through a nip 24 of an S-roil arrangement 26 formed by the stack rollers 28 and 30.
  • the nonwoven substrate 20 may be formed from known continuous and ⁇ o ⁇ continuous filament or fiber nonwoven extrusion processes.
  • continuous fiber nonwoven extrusion processes include, but are not limited to, known solvent spinning or meltspinning processes such as, for example a spunbonding process. See for example U.S. Patent Number 3.692.618 to Dorschner et al., U. S. Patent Number 4,340,563 to Appel et al. and U.S. Patent Number 5,382,400 to Strack et al. which are incorporated herein by reference in their entirety.
  • -Examples of known no ⁇ co ⁇ ti ⁇ uous fiber nonwoven extrusion processes include those which use preformed staple length fibers such as bonded carded web forming processes. Of particular use with the present invention are known processes for forming through-air bonded carded webs. These processes may be utilized in-line or the substrate 20 be formed off-line and then brought into the present process as in the form of the supply roll 22 shown in Figure 3.
  • Bonded carded webs are made from staple fibers which are usually purchased in bales. The bales are placed in a picker which separates the fibers. Next, the fibers are sent through a combing or carding unit which further breaks apart and aligns the staple fibers in the machine direction so as to form a machine direction-oriented fibrous nonwoven web. Once the web has been formed, it is then bonded by one or more of several bonding methods.
  • One bonding method is powder bonding wherein a powdered adhesive is distributed throughout the web and then activated, usually by heating the web and adhesive with hot air.
  • Another bonding method is pattern bonding wherein heated calendar rolls or ultrasonic bonding equipment is used to bond the fibers together, usually in a localized bond pattern though the web can be bonded across its entire surface if so desired.
  • the best method though, when using bicompo ⁇ ent staple fibers is to use a through-air bonder such as is described above with respect to the bicompo ⁇ ent spu ⁇ bond web formation process.
  • the bonding process used to bond the fibers of the fibrous nonwoven web together should be a process such as through-air bonding which does not unduly compress or collapse the structure during the formation process.
  • Airlaying is another well known process by which fibrous nonwoven webs according to the present invention can be made.
  • bundles of small fibers usually having lengths ranging between about 6 and about 19 miliimeters are separated and entrained in an air supply and then deposited onto a forming screen, oftentimes with the assistance of a vacuum supply.
  • the randomly deposited fibers are then bonded to one another using, for example, hot air or a spray adhesive.
  • Bonding processes such as point bonding and pattern bonding using smooth and/or pattern bonding rolls may create a resultant fibrous nonwoven web which is too dense and does not have the degree of voids necessary for the present invention. Whatever process is chosen, the degree of bonding will be dependent upon the fibers/polymers chosen but, in any event, it is desirable that there be as little compression as possible during the heating stage.
  • the pulp fiber iayer 18 and the nonwoven substrate 20 are brought together upon a foraminous entangling surface 32 which passes through a conventional hydraulic entangling machine 34 which includes hydraulic entangling manifolds 35. It is desirable that the pulp layer 18 be positioned between the nonwoven substrate 20 and the hydraulic entangling manifolds 35. As the pulp layer 18 and nonwoven substrate 20 pass through the machine 34, they are treated with jets of liquid which force the pulp fibers into the matrix fibers of the nonwoven substrate 20 thereby entangling the pulp fibers with the nonwoven matrix fibers to form the entangled pulp and nonwoven composite 36 of the present invention.
  • the hydraulic entangling may be accomplished utilizing conventional hydraulic entangling equipment such as may be found in, for example, U.S. Patent No. 3,485,706 to Evans and U.S. Patent No. 5,284,703 to Everhart et al. both of which are incorporated herein by reference in their entirety.
  • the hydraulic entangling may be carried out with any appropriate working fluid such as, for example, water.
  • the working fluid flows through one or more manifolds 35 which evenly distribute the fluid to a series of individual holes or orifices.
  • the holes or orifices may be from about 0.003 to about 0.015 inches (0.076 to 0.38 millimeters) in diameter.
  • the invention may be practiced utilizing a manifold produced by Honeycomb Systems, Inc.
  • the working fluid passes through the orifices at a pressure ranging from about 200 to about 2000 pounds per square inch gage (psig) (about 1379 kilopascals to about 13,790 kiiopascals).
  • psig pounds per square inch gage
  • An important feature of the present invention is that there not be complete integration of the530p fibers into the matrix fibers of the nonwoven layer or substrate 20. As a result, it will be necessary to adjust both the pressure and the line speed of the process to achieve the desired limited degree of integration. Also, the number of manifolds 35 and the pressure within each manifold will affect the degree of integration as wiil the basis weight of the nonwoven substrate into which the pulp fibers are integrated.
  • the fluid impacts the pulp fiber layer 18 and the nonwoven substrate 20, both of which are supported by a foraminous surface 32 which may be, for example, a single plane mesh wire having a mesh size of from about 40x40 strands per inch (15.7 x 15.7 strands per centimeter) to about 100x100 strands per inch (39.4 x 39.4 strands per centimeter).
  • the foraminous surface 32 also may be a multi-ply mesh having a mesh size from about 50x50 to about 200x200 strands per inch (19.7 x 19.7 to about 78.7 x 78.7 strands per centimeter).
  • vacuum slots 38 may be located directly beneath the hydro-needling manifolds 35 or beneath the foraminous entangiing surface 32 downstream of the manifolds 35 so that excess water can be withdrawn from the entangled composite material 36.
  • the composite material or fabric 36 may be transferred to a non-compressive drying operation or a compressive drying operation such as steam cans (not shown).
  • a differential speed pick-up roll 40 may be used to transfer the material from the hydraulic needling belt to a non-compressive drying operation.
  • conventional vacuum-type pick-ups and transfer fabrics may be used.
  • the composite fabric may be wet creped before being transferred to the drying operation.
  • Non-compressive drying of the web may be accomplished utilizing a conventional rotary drum through-air dryer 42.
  • the through-air dryer 42 may be an outer rotatable cylinder 44 with perforations 46 in combination with an outer hood 48 for receiving hot air blown through the perforations 46.
  • a through-dryer belt 50 carries the composite fabric 36 over the upper portion of the through- dryer outer cylinder 44.
  • the heated air forced through the perforations 46 in the outer cylinder 44 of the through-dryer 42 removes water from the composite fabric 36.
  • the temperature of the air forced through the composite fabric 36 by the through-dryer 42 may range from about 93° Celsius (C) to about 260° C (200° F to about 500° F).
  • C 93° Celsius
  • Other useful through-drying methods and apparatus may be found in, for example, U.S. Patent Nos. 2,666,369 and 3,821,068 both of which are incorporated herein by reference in their entirety.
  • the fabric may be lightly pressed by calendar rolls, creped or brushed to provide a uniform exterior appearance and/or certain tactile properties.
  • chemical post-treatments such as surfactants, adhesives or dyes may be added to the fabric.
  • the fabric may contain various materials such as, for example, activated charcoal, clays, starches, and superabsorbe ⁇ t materials. For example, these materials may be added to the suspension of pulp fibers used to form the530p fiber layer. These materials may also be deposited on the530p fiber layer prior to the fluid jet treatments so that they become incorporated into the composite fabric 36 by the action of the fluid jets.
  • these materials may be added to the composite fabric after the fluid jet treatments.
  • superabsorbe ⁇ t materials are added to the suspension of pulp fibers in the131p fiber layer before water-jet treatment, it is preferred that the superabsorbents are those which can remain inactive during the wet-forming and/or water jet treatment steps and which can be activated later.
  • Conventional superabsorbents may be added to the composite fabric after the water-jet treatment. See for example U.S. Patent No. 5.328,759 to McCormack et al. which is incorporated herein by reference in its entirety.
  • Useful superabsorbents include, for example, a sodium polyacrylate superabsorbent available from the Hoechst Cela ⁇ ese Corporation under the trade designation Sanwet IM- 5000 P.
  • Superabsorbents may be present at a proportion of up to about 50 grams of superabsorbe ⁇ t per 100 grams of pulp fiber. They may be used in various forms including, for example, particles, flakes and fibers. Having described the materials and orocess of the present invention in detail, several examples were prepared to demonstrate the present invention. These examples as well as the test procedures to measure them are set forth below.
  • the composite structures of the present invention were tested to determine how rapidly each would absorb 2 cubic centimeters of an artificial menstrual fluid.
  • the formulation of the synthetic menstrual fluid is on a weight percent basis, approximately 82.5% water, 15.8% polyvinyi pyrroiidone and 1.7% salts, coloring agents, and surfactants. It has a viscosity of 17 centipoise, and a surface tension of 53.5 dynes per centimeter.
  • the test utilizes a test apparatus which consisted of 1) a Lucite* block and 2) a flat, horizontal test surface.
  • FIG 4 is a plan view of the Lucite* block.
  • Figure 5 is a sectional side view of the Lucite* block.
  • the block 200 has a base 202 which protrudes from the bottom of the block.
  • the base 202 has a flat surface 204 which is approximately 2.875 inches (7.3 centimeters) long by 1.5 inches (3.8 centimeters) wide and which forms the bottom of the block 200.
  • An oblong opening 206 (about 1.5 inches (3.8 cm) long by about 0.25 inches (0.64 cm) wide) is located in the center of the block and extends from the top of the block to the surface 204 of the base 202 of the block. When the bottom of the opening 206 is obstructed, the opening 206 can hold about 10 cubic centimeters of fluid.
  • a mark 207 on the block 200 indicates a liquid level of about 2 cubic centimeters.
  • a funnel 208 on the top of the block feeds into a passage 210 which is connected to the obiong opening 206. Fluid is poured down into funnel 208 ana passes through the passage 210 into the oblong opening 206 and out onto a test sample underneath the block.
  • Each sample (7.6 cm X 17.8 cm) was tested by placing it on a flat, acrylic, horizontal test surface and then putting the flat, projecting base of the block on top of the sample (nonwoven side up/pulp side down) so that the long dimension of the oblong opening 206 was parallel to the long dimension of the sample and centered between the ends and sides of the sampie.
  • the weight of the block was about 163 grams so that the block rested on the sampie with a pressure of about 7 grams per square centimeter.
  • Approximately 4 cubic centimeters of the artificial menstrual fluid was dispensed into the funnel from a Repipet (catalogue No.13- 687-20; Fischer Scientific Company).
  • a stopwatch was started when the forward front of the liquid passed the mark 207.
  • the fiuid filled the oblong opening of the block and the watch was stopped when the trailing meniscus of the fluid passed the mark 207 thereby indicating that 2 cubic centimeters of fluid had been absorbed.
  • the amount of time to absorb the 2 cubic centimeters of artificial menstrual fluid was then recorded. This value was then converted to cubic centimeters per minute. Ten repetitions were performed for each sample and an average was then calculated.
  • the cup crush test was used to evaluate fabric stiffness by measuring the peak load required for a 4.5 centimeter diameter hemispherically-shaped foot to crush a 9.0 inch by 9.0 inch (22.9 centimeter by 22.9 centimeter) piece of fabric shaped into an approximately 6.5 centimeter diameter by 6.5 centimeter tall inverted cup while the cup shaped fabric was surrounded by an approximately 6.5 centimeter diameter cylinder to maintain a uniform deformation of the cup shaped fabric.
  • the foot and cup were aligned to avoid contact between the cup walls and the foot which could affect the peak load.
  • the peak load was measured while the foot was descending at a rate of about 0.25 inches per second (0.64 centimeters per second) which is equivalent to 15 inches per minute (38.1 centimeters per minute) utilizing a Model 3108-128 10 pound load ceil (4.54 kg load cell) available from the MTS Systems Corporation of Cary, North Carolina. A total of seven to ten repetitions were performed for each material and then averaged to give the reported values.
  • the basis weights for the samples were determined in accordance with Federal Test Method 191 A/5041. Sample sizes were 9 inches by 9 inches (22.9 centimeters by 22.9 centimeters). A total of seven to ten samples were weighed and averaged.
  • the cohesion strength of the composite was measured by measuring the cohesion force between the two layers of the composite material. The minimum force required to separate the two layers was given in kilograms of force per square inch.
  • the cohesion force of a one inch square (6.45 square centimeters) sample was measured using a Chatillon Digital Force Gauge Model DFI 50 from John Chatillon and Sons, Inc. of Greensboro, North Carolina.
  • the device had a pneumatically operated base plate measuring 2 inches (5.1 cm) by 4 inches (10.2 cm) and a one inch (2.54 cm) square top plate which was connected to a digital force gauge.
  • Double-faced adhesive tape was applied to both the base plate and the top plate and a 2 inch (5.1 cm) by 4 inch (10.2 cm) sample of material was positioned on top of the 2 inch by 4 inch base plate.
  • the tape used to cover the surfaces of both the base plate and the top plate was Scotch ® Brand double-coated pressure-sensitive tape number 406 which is available in 1-inch (2.54 cm) and 2-inch (5.1 cm) widths.
  • the two inch wide tape was used for the base plate and the one inch wide tape was used for the top plate.
  • the ⁇ emand absorbency test measures the intake rate in grams per minute of an absorbent material at zero hydrostatic head (pressure). It was conducted in accordance with the test entitled " DEMAND WETTABILITY, A NEW METHOD FOR MEASURING ABSORBENCY CHARACTERISTICS OF FABRICS " written by Bernard M. Lichstein of the Johnson and Johnson Company of New Brunswick, New Jersey 08903 which was given and published at the 1974 INDA Technical Symposium (pages 129 through 142). INDA (the Association of the Nonwoven Fabrics Industry) has offices at 1001 Winstead Drive, Suite 460, Cary, North Carolina. The test apparatus used in the present instance was different than that described in the above test. The actual test apparatus is shown in Figure 6 of the drawings.
  • the test apparatus 300 included a 400 milliliter bottle 310 with a side exit hole 312.
  • the bottle 310 was filled with the same synthetic menstrual fluid 314 as was described earlier and was placed on top of a Sartorius scale 316 model number 1413 mp8- 1 to allow gram per unit time data to be recorded as the test samples drew fluid from the bottle and therefore reduced its weight.
  • the top of the bottle 310 was plugged with a single hole rubber stopper 318. Through the hole in the stopper there was placed a 0.6 cm (OD) glass tube 320.
  • the glass tube 320 was placed sufficiently deep within the bottle so as to ensure that its open bottom end remained submerged in the synthetic menstrual fluid 314 throughout the test.
  • the rubber stopper/glass tube combination replaced the air bleed system described in the test procedure.
  • the sample materials 322 were positioned, ⁇ onwoven-rich side down, on top of a 12.7 centimeter by 22.9 centimeter acrylic plate 324 which had a 1.59 centimeter diameter hole 326 positioned in the middle of the top of the plate.
  • the hole descends 0.5 cm before reducing in diameter to 1.0 cm and then descends an additional 0.8 cm. It then takes a right turn, then exits the side of the plate at hole 330.
  • the bottle 310 was connected to the plate 324 using a Tygo ⁇ ® plastic tube 328 having an inner diameter of 0.635 centimeters and a wall thickness of 0.159 centimeters.
  • the tube 328 was fitted into a 0.95 centimeter diameter hole 330 in the side of the piate 324 which was in fluid communication with the plate hole 326.
  • the samples which had dimensions of 17.6 centimeters by 7.6 centimeters were positioned on top of the plate 324 such that the each sample was centered over top of the plate hole 326 and the long dimension of the sample corresponded to the long dimension of the plate. No top plate was placed over the sampie as described in the test procedure. As a result, the test samples were under no compressive force during the absorption of fluid. To conduct the test, the operator should ensure that the submerged tip of the glass tube 320 and the top surface of the plate 324 are at the same elevation.
  • a stopwatch or other suitable timing device is started.
  • fluid is drawn out of the bottle and is replaced by air through the glass tube causing air bubbles to percolate up through the remaining fluid 314 in the bottle 310.
  • the loss of fluid from the bottle 310 is shown on the scate 316 as a loss of mass.
  • the time in seconds to reduce the weight on the scale by one gram is recorded as grams per number of seconds. This value is then multiplied by the conversion factor 60 seconds/one minute to yield the absorption rate in number of grams per minute. A total of 5 to 7 tests were run and averaged to yield the results reported below.
  • Example materials were prepared as described below. With respect to Examples 1 through 4 there were three different embodiments tested.
  • the " a" sample was a hydroentangled sample according to the present invention.
  • the " b" sampie was the component materials laid one on top of the other but with no attachment of the materials to one another.
  • the " c " sample was the same two materials adhesively attached to one another.
  • the adhesive used was 3M Super 77-N Spray Adhesive produced by the 3M Corporation of St. Paul, Minnesota. Add-on of the adhesive was between about 10 and about 25 grams per square meter.
  • the samples in Examples 1, 2 and 4 utilized a si ⁇ gie layer of nonwoven with a pulp sheet to form the composite while Example 3 utilized a two layer nonwoven and a pulp sheet to form the composite.
  • Example 5 was a pulp sheet only. As a result, there were no samples a, b and c in Example 5. Intake rates were calculated for samples 1a, 2a, 3a, 4a and 5 only.
  • a two layer composite was formed using a bonded carded web and a pulp sheet.
  • the bonded carded web was a through- air bonded carded web or TABCW.
  • the web included on a weight percent basis based upon the total weight of the web: 40 percent 6.0 denier polyester stapie fibers having a length of 38 millimeters and 60 percent 3.0 denier polyethylene sheath/polyester core bicompo ⁇ ent fibers having a length of 38 millimeters.
  • the polyester fibers were obtained from the Hoechst Cela ⁇ ese Corporation of Spartanburg, South Carolina.
  • the bicompone ⁇ t fibers were obtained from the BASF Wyandotte Corporation of Parsippany, New Jersey and were designated as being from merge 1-1039.
  • the fibers were all sent through an opener and were uniformly mixed together before being carded into a web. Once the web was formed, it was then sent through a through-air bonder with an air temperature of 135° C. The dwell time within the bonder was about 4 seconds. The resultant web had a basis weight as calculated above of 48.8 grams per square meter (gsm). During the bonding process, the samples were compressed from an initial thickness of approximately 200 mils (0.518 cm) to a final thickness of approximately 100 mils (0.259 cm) at a pressure of 689 dynes/square cm. The web was wound up on a roll and then transferred to an apparatus similar to that shown in Figure 1 of the drawings.
  • the pulp sheet was formed using conventional pulp sheet forming equipment. Into the repulper there was placed on a weight percent basis not counting the water in the repulper: 49.5 percent Longlac northern softwood fibers available from the Kimberly-Clark Corporation, 49.5 percent Coosa River 54 southern softwood fibers also available from the Kimberly-Clark Corporation and 1.0 percent PA727 Arosurf chemical debonder from the Witco/Sherex Chemical Company, Inc. of Dublin, Ohio. The pulp fibers and debonder were mixed as a slurry for approximately 15 minutes. A wet laid memep sheet was formed from the slurry having a basis weight of approximately 75 grams per square meter.
  • the nonwoven web was brought into the forming process under the wet laid pulp sheet and the combination was passed through a hydroentangling apparatus which included four manifolds.
  • the pulp sheet and nonwoven were supported on a 100 mesh stainless steel forming wire with the nonwoven positioned adjacent the wire.
  • the line speed through the hydroentangling apparatus was 6.1 meters per minute (20 feet per minute).
  • Each manifold was fitted with a single row of water jets with a hole density of 11.8 holes per centimeter (30 holes per inch) and an overall width in the cross machine direction of approximately 46 centimeters.
  • the hole diameter of each of the holes in the water jet was 0.01778 centimeters (cm) (0.007 inches).
  • Each of the manifolds was adjusted for its individual pressure.
  • the upstream manifold was adjusted to have a pressure of 250 pounds per square inch gauge (1724 kilopascals) and the other three manifolds were all adjusted to a pressure of 400 pounds per square inch gauge (2758 kilopascals).
  • a surfactant solution which contained 80 liters of deionized water, 240 grams of n-hexa ⁇ ol and 600 grams of Y-12488 organosiloxane surfactant from the Union Carbide Chemical and Plastics Company of Danbury, Connecticut.
  • the mixture was stirred in a vat at room temperature for 10 minutes and then sprayed onto the nonwoven side of the composite so as to impart to the overall web a concentration of 1.0 percent by weight based upon the total weight of the composite web.
  • the composite web was sent through a through-air dryer set to a drying temperature of 149° C (300° F). The dwell time within the dryer was approximately 23 seconds.
  • the resultant material had a basis weight of approximately 125 grams per square meter.
  • Sample 1b was the same nonwoven layer and the same pulp sheet.
  • Sampie 1c used the same materials as sampie 1b, the only difference being that the two layers of material were adhesively attached to one another.
  • the adhesive add-on was approximately 25 gsm.
  • Example 1a Basis weight, fluid intake rates, cup crush loads, cohesion force and demand absorbency rates for the composites were measured and are reported in Tables 1 and 2.
  • the composite material produced in this manner had a combination of good fluid properties.
  • the lofty nonwoven side of the composite provided an intake/surge functionality which is important when the material is used as an intake portion of a personal care absorbent article such as a sanitary napkin.
  • the nonwoven acts to readily absorb fluids discharged from the body, hold them and then transfer them to the pulp portion of the composite.
  • the pulp portion of the composite provides both retention capacity and the ability to directionaily distribute fluids along the machine direction of the material due to the fiber alignment of the pulp fibers during the hydroentangling process.
  • Another important factor contributing to the fluid distribution is the zone in which the pulp fibers are entangled with the nonwoven fibers. This area of intimate contact interface improves fluid transport from the nonwoven surge/distribution layer into the pulp distribution/absorbent layer.
  • Example 2a a two layer composite was formed using a bonded carded web and a pulp sheet.
  • the bonded carded web was a through- air bonded carded web which included on a weight percent basis based upon the total weight of the web: 25 percent 1.5 denier rayon staple fibers having a length of 39.7 millimeters, 35 percent 3.0 denier polyethylene sheath/polyester core bicomponent fibers having a length of 38 millimeters and 40 percent 6.0 denier polyester staple fibers having a length of 38 millimeters.
  • the rayon staple fibers were obtained from Courtaulds North America, Inc. of New York, New York and were designated as being from lot number 18543.
  • the bicomponent fibers were obtained from the BASF Wyandotte Corporation of Parsippany, New Jersey and were designated as being from merge 1-1039.
  • the polyester staple fibers were obtained from the Hoechst Celanese Corporation of Spartanburg, South Carolina and were designated T- 295.
  • the staple fibers were all sent through an opener twice and were uniformly mixed together before being carded into a web at a line speed of 15.24 meters per minute (50 feet per minute). Once the web had been formed, it was then sent through a through-air bonder (drum type) with an air temperature of 163°C (325°F). The dwell time within the bonder was between about 3 and about 4.5 seconds. The resultant web had a basis weight as calculated above of 50 grams per square meter (gsm). The web was wound up on a roll and then transferred to an apparatus simiiar to that shown in Figure 1 of the drawings.
  • the 75 gsm pulp sheet was the same as that used in Example 1.
  • the pulp sheet and the bonded carded web were brought together and entangled under the same conditions as were used in Example 1.
  • the 125 gsm composite material had the same good properties as the composite in Example 1.
  • Sample 2b used the same materials as sampie 2a with the same modifications as outlined above with respect to sample 1b.
  • Sample 2c was made from the same materials as sample 2b. Adhesive add-on for sampie 3c was approximately 20 gsm.
  • Example 3a a 75 gram per square meter530p sheet was used which had the same fiber and debonder formulation as in Example 2.
  • the nonwoven web into which it was integrated was in this case a two layer bonded carded web having a total basis weight of 50 grams per square meter.
  • the top layer of the nonwoven web was a 17 gram per square meter through-air bonded carded web made entirely from 1.8 denier polyethylene sheath/polyester core bicomponent fibers having a length of 38 millimeters. These fibers were obtained from the BASF Wya ⁇ dotte Corporation of Parsippany, New Jersey.
  • the bottom layer of the two layer bonded carded web was a 33 gram per square meter homogeneous blend of 30 weight percent 1.5 denier rayon fibers (the same as were used in Example 2) and 70 percent 3.0 denier polyethylene sheath/polyester core bicomponent fibers (again the same as were used in Example 2). The weight percents were based upon the total weight of the bottom iayer.
  • the two layers were through-air bonded together using the same equipment as in Example 2.
  • the bonding temperature was 163° C. and the dwell time within the through-air bonder was approximately 3 to 4.5 seconds.
  • the wet pulp sheet was brought into the hydroentangling apparatus on top of the two layer bonded carded web.
  • the bonded carded web was positioned such that the pulp sheet contacted the bottom layer.
  • only three of the four manifolds were used in this exampie. All three of the manifolds were adjusted to a gauge pressure of 400 psig (2758 kilopascais). The line speed remained the same at 6.1 meters per minute.
  • the nonwoven side of the composite was sprayed with the same surfactant solution as was used in Examples 1 and 2 and the application rate was also the same.
  • the composite web was then dried in the same fashion as the previous samples at a temperature of 138°C.
  • Samples 3b and 3c were made in the same fashion as their counterpart samples in the previous examples using the same materials as in sample 3a.
  • the promisp sheet was hydroentangied in the same manner as samples 1b and 2b.
  • Adhesive add-on for sample 3c was approximately 18 gsm.
  • this laminate when coupled with a liquid impervious material adjacent the pulp side could be used as, for example, a thin pantiliner. Furthermore, unlike layered products or products which have the iayers adhesively attached to one another, this entangled structure had increased fluid handling and a decreased ply separation as shown by the data in Tables 1 and 4.
  • Example 4a a two layer composite was produced using a spunbond web and a pulp sheet.
  • the spunbond web was a through- air bonded bicomponent fabric which was produced as described in U.S. Patent Number 5,382,400.
  • the approximately 2 to 3 denier bicomponent spunbond fibers were 50% polypropylene and 50% polyethylene (on a weight percent basis) arranged in a side-by-side configuration.
  • a 34 grams per square meter fabric of crimped bicomponent fibers was produced, through air bonded and delivered to the entangling process.
  • the pulp portion of the composite was produced essentially as in Example 1 except for the basis weight, which was reduced to 70 grams per square meter. To this pulp sheet was added the bicomponent spunbond web. The entangling process was as described in -Example 1, however, this composite was produced with three manifolds of water jets adjusted to 2758 kilopascals (kPa).
  • samples 4b and 4c were also prepared. Add-on for the adhesive in sample 4c was approximately 11 gsm.
  • Example 5 was a pulp sheet control made to measure and compare the fluid intake rate of pure hydroentangled pulp (See Table 1).
  • the pulp sheet was 75 gsm and was made in the same fashion as the other pulp sheets. Hydroentangling was done using three manifolds adjusted to a pressure of 250 psig (1724 kPa).
  • a comparison of the intake rate data in Table 1 illustrates the benefits of the addition of a matrix fiber (nonwoven web) to a pulp sheet.
  • the matrix fibers provide a nonwoven rich side to the composite which can more quickly absorb available fluid as compared with the slower pulp sheet in -Example 5. This rapid intake eliminates free fluid which couid by-pass the absorbent and cause premature product failure.
  • Tables 2 through 5 illustrate three methods of adding together matrix and pulp sheet fibers.
  • the " a " sample represented the entangled structure according to the present invention while the “ b " sampie contained no bonding or entanglement between the layers of material.
  • the " c " sample supplanted the entangling of the two layers with adhesive attachment. Cohesion measures the attachment of the components and was highest in the entangled materials, samples " a " .
  • Increasing the adhesive level of samples " c " would increase the cohesion but as can be seen from the cup crush data, the adhesively bonded samples were already much stiffer than the entangled samples. By far the most significant impact off entangling can be seen in the demand absorbency data.
  • the entangled structures can absorb fluid at a much faster rate than alternative structures. This is believed to be due to the enhanced fluid pathways provided by the pulp fibers which extend into the matrix fibers of the composite.
  • the photomicrographs show how the ribbon-like memep fibers can be seen projecting up into the low density matrix fibers. When samples are layered or adhesively attached together, the pulp fibers do not extend into the matrix fibers. In the " b " samples there was a layer of air between the pulp fiber layer and the matrix fiber layer. In the " c" samples there was an adhesive layer between the layers of pulp fibers and matrix fibers. In both cases the net effect was a limited pathway for iiquid flow from one portion of the structure to the other. This was proven by the iow demand absorbency data results for the non-hydroe ⁇ tangled samples.
  • Personal care absorbent articles include, for example, diapers, training pants, incontinence devices, bandages and feminine hygiene products such as sanitary napkins and pantiliners.
  • Pantiliners are a much thinner version of sanitary napkins which are worn on light flow days and/or in addition to tampons by many women.
  • Most personal care absorbent articles such as the pantiliner 400 include a backing sheet 402 which is usually liquid impervious and an absorbent core 404 such as wood530p fibers with or without superabsorbe ⁇ t admixed therewith.
  • absorbent core 404 such as wood530p fibers with or without superabsorbe ⁇ t admixed therewith.
  • such articles can optionally include a body side liner or top sheet 406 for placement adjacent the wearer ' s skin.
  • the two layer hydroentangled materials can be used as the absorbent core 404 in conjunction with the backing sheet 402 to form, for example, a pantiliner 400.
  • the pulp-rich side of the composite is positioned adjacent the backing sheet 402 and the matrix-rich side of the composite is positioned adjacent the wearer.
  • the matrix-rich side will function to readily take in fluids which will then be transferred to the pulp-rich side of the absorbent composite via the hydroentangled interior portion. In so doing, the fluid is removed from the vicinity of the wearer ' s skin and is stored in the pulp fibers adjacent to backing sheet.

Landscapes

  • Engineering & Computer Science (AREA)
  • Textile Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Nonwoven Fabrics (AREA)
  • Absorbent Articles And Supports Therefor (AREA)

Abstract

L'invention concerne un composite non-tissé entremêlé constitué de fibres absorbantes, telles que des fibres de pâte de bois, et de fibres matricielles telles que des fibres discontinues de polyoléfine. Ces fibres absorbantes sont entremêlées avec les fibres matricielles de telle manière que le composite présente une face riche en fibres absorbantes et une face riche en fibres matricielles. Entre les deux faces extérieures se trouve une portion intérieure entremêlée constituée d'un mélange des fibres absorbantes et des fibres matricielles. Ce composite se prête particulièrement bien au traitement multifonctions de fluides tels que, par exemple, des fluides biologiques absorbés par des articles absorbants d'hygiène personnelle. La portion en fibres matricielles du composite constitue une région d'entrée des fluides tandis que la portion en fibres absorbantes constitue une région de rétention des fluides et la portion du composite entre les deux surfaces extérieures constitue une région de transfert des fluides.
PCT/US1996/011653 1996-07-12 1996-07-12 Composites non-tisses entremeles par procede hydrique WO1998002608A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
PCT/US1996/011653 WO1998002608A1 (fr) 1996-07-12 1996-07-12 Composites non-tisses entremeles par procede hydrique
AU64574/96A AU6457496A (en) 1996-07-12 1996-07-12 Hydroentangled nonwoven composites

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US1996/011653 WO1998002608A1 (fr) 1996-07-12 1996-07-12 Composites non-tisses entremeles par procede hydrique

Publications (1)

Publication Number Publication Date
WO1998002608A1 true WO1998002608A1 (fr) 1998-01-22

Family

ID=22255447

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1996/011653 WO1998002608A1 (fr) 1996-07-12 1996-07-12 Composites non-tisses entremeles par procede hydrique

Country Status (2)

Country Link
AU (1) AU6457496A (fr)
WO (1) WO1998002608A1 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003002162A1 (fr) * 2001-06-27 2003-01-09 Kimberly-Clark Worldwide, Inc. Composites absorbants a base de pulpe et de fibres synthetiques destines a des produits de soins personnels
EP2692321A1 (fr) * 2012-08-03 2014-02-05 Sandler AG Matelas d'accumulateur intermédiaire
EP2735632A1 (fr) * 2012-11-21 2014-05-28 Kang Na Hsiung Enterprise Co. Ltd. Tissu non tissée et son procédé de fabrication

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0308320A2 (fr) * 1987-09-15 1989-03-22 Fiberweb North America, Inc. Etoffe non tissée solide
EP0492554A1 (fr) * 1990-12-21 1992-07-01 Kimberly-Clark Corporation Etoffe non tissée composite avec une haute teneur en poudre de fibres, méthode de réalisation et utilisation
EP0540041A1 (fr) * 1991-11-01 1993-05-05 Kimberly-Clark Corporation Procédé de production d'un matériau composite super-absorbant aiguilleté hydrauliquement
WO1996007783A1 (fr) * 1994-09-03 1996-03-14 British United Shoe Machinery Limited Materiau absorbant et procede de fabrication

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0308320A2 (fr) * 1987-09-15 1989-03-22 Fiberweb North America, Inc. Etoffe non tissée solide
EP0492554A1 (fr) * 1990-12-21 1992-07-01 Kimberly-Clark Corporation Etoffe non tissée composite avec une haute teneur en poudre de fibres, méthode de réalisation et utilisation
EP0540041A1 (fr) * 1991-11-01 1993-05-05 Kimberly-Clark Corporation Procédé de production d'un matériau composite super-absorbant aiguilleté hydrauliquement
WO1996007783A1 (fr) * 1994-09-03 1996-03-14 British United Shoe Machinery Limited Materiau absorbant et procede de fabrication

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003002162A1 (fr) * 2001-06-27 2003-01-09 Kimberly-Clark Worldwide, Inc. Composites absorbants a base de pulpe et de fibres synthetiques destines a des produits de soins personnels
US6759567B2 (en) 2001-06-27 2004-07-06 Kimberly-Clark Worldwide, Inc. Pulp and synthetic fiber absorbent composites for personal care products
EP2692321A1 (fr) * 2012-08-03 2014-02-05 Sandler AG Matelas d'accumulateur intermédiaire
EP2735632A1 (fr) * 2012-11-21 2014-05-28 Kang Na Hsiung Enterprise Co. Ltd. Tissu non tissée et son procédé de fabrication

Also Published As

Publication number Publication date
AU6457496A (en) 1998-02-09

Similar Documents

Publication Publication Date Title
EP0830470B1 (fr) Composites non tisses enchevetres par procede hydraulique
JP2533260B2 (ja) パルプ含有率の高い不織複合布
US6784126B2 (en) High pulp content nonwoven composite fabric
JP3083602B2 (ja) 水圧を用いてニードルした不織パルプ繊維ウェブ
US6479415B1 (en) Absorbent structures having fluid acquisition and distribution layer
EP1703882B1 (fr) Protege-slip absorbant a profil extra-plat
KR20030093195A (ko) 합성 섬유가 혼입된 흡수 물질 및 이의 제조 방법
KR20010093188A (ko) 개인용 위생 제품에 사용하기 위한 탄성 유체 처리 물질
JPH06158501A (ja) フィルム積層材料及びその製造方法と製造装置
TW200300077A (en) Cover sheet for personal care products and process for manufacturing the same.
AU748366B2 (en) Absorbent structures having fluid distribution and storage layers
KR102587446B1 (ko) 액체 취급이 개선된 여성 위생 용품
KR20040029395A (ko) 높은 습윤 전 및 후 투과도를 갖는 부직 복합물
MXPA02002666A (es) Tels plegadas fibrosas.
WO1998002608A1 (fr) Composites non-tisses entremeles par procede hydrique
CA2165107A1 (fr) Nontisse composite a teneur elevee en fibres
JP2533260C (fr)
MXPA00012252A (en) Absorbent structures having fluid distribution and storage layers
MXPA06007746A (en) Low profile absorbent pantiliner

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AL AM AT AU AZ BB BG BR BY CA CH CN CZ DE DK EE ES FI GB GE HU IS JP KE KG KP KR KZ LK LR LS LT LU LV MD MG MK MN MW MX NO NZ PL PT RO RU SD SE SG SI SK TJ TM TR TT UA UG UZ VN AM AZ BY KG KZ MD RU TJ TM

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): KE LS MW SD SZ UG AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE BF BJ CF CG CI CM GA GN ML

121 Ep: the epo has been informed by wipo that ep was designated in this application
REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

NENP Non-entry into the national phase

Ref country code: JP

Ref document number: 98505944

Format of ref document f/p: F

NENP Non-entry into the national phase

Ref country code: CA

122 Ep: pct application non-entry in european phase
122 Ep: pct application non-entry in european phase