# US 4,573,988 A · Superthin absorbent product > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,573,988 A - Document ID: US4573988A - Status: Granted - Kind: A - Application number: 06/607,379 - Filed: 1984-05-07 - Granted: 1986-03-04 - Earliest claimed: 1982-11-08 - Assignees: Personal Products Company - Inventors: Heinz A. Pieniak; Michael J. Iskra - Web page: https://patentgrep.com/patent/US4573988A ## CPC - A61F 13/534: having an inhomogeneous composition through the thickness of the pad (A61F13/538, A61F13/539 take precedence) - A61F 13/2051: {characterised by the material or the structure of the inner absorbing core} - A61F 13/53713: {the layer having a promotional function on liquid propagation in the vertical direction} - A61F 13/53747: {the layer is facing the topsheet (layer is part of the topsheet A61F13/511)} - A61F 13/53756: {the layer facing the back-sheet} - A61F 13/202: {Catamenial tampons (A61F13/2022-A61F13/34 take precedence)} - A61F 13/58: Adhesive tab fastener elements ({A61F13/5611, A61F13/5616}, A61F13/66 take precedence) - A61F 2013/15048: {for protection against contamination, or protection in using body disinfecting wipes} - A61F 2013/51409: {being a film} - A61F 2013/530131: {being made in fibre but being not pulp} - A61F 2013/530306: {coated with superabsorbent polymer} - A61F 2013/530335: {being in peat moss} - A61F 2013/53043: {with different ratio of components} - A61F 2013/530481: {having superabsorbent materials, i.e. highly absorbent polymer gel materials} - A61F 2013/530496: {being fixed to fibres} - A61F 2013/583: {with strips on several places} - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) ## Abstract A superthin absorbent disposable product is provided having an absorbing layer containing superabsorbent and a wicking layer. The product is suitable for use in disposable diapers, sanitary napkins, incontinent pads, wipes and the like. ## Claims ### Claim 1 A disposable absorbent compressed composite comprising a first layer, a second layer, and a transition zone integrally and intimately connecting said first and second layers, said first layer comprising a fibrous web having a dry bulk recovery of at least about 30 percent, an initial dry bulk of at least about 40 cc/gm, a wet bulk of at least about 30 cc/gm and a weight less than about 4 oz/yd.sup.2, and a plurality of particles of superabsorbent material disposed intermittently throughout said first layer, said superabsorbent particles being present in at least about 200 percent dry-add-on basis, said second layer comprising substantially uniformly disposed, hydrophilic particles selected from the group consisting of cellulosic fibers, peat moss, rayon fibers, acrylic fibers, and mixtures thereof, said particles being sufficiently closely spaced to adjacent particles to promote rapid movement of liquid along the plane of said layer, and said transition zone comprising portions of said hydrophilic particles extending into and becoming integral with said first layer with portions of said hydrophilic particles in intimate contact with said superabsorbent material, said composite being compressed substantially reduce its thickness. ### Claim 2 (depends on 1) The compressed composite of claim 1 wherein said first layer comprises a nonwoven web of synthetic staple fibers. ### Claim 3 (depends on 2) The compressed composite of claim 2 wherein the nonwoven web comprises polyester fibers. ### Claim 4 (depends on 1) The compressed composite of claim 1 wherein the thickness of the composite is less than one-half its thickness in uncompressed form. ### Claim 5 (depends on 1) The compressed composite laminate of claim 1 wherein said second layer comprises chemically delignified wood pulp fibers. ### Claim 6 (depends on 1) The compressed composite laminate of claim 1 wherein said second layer comprises peat moss. ### Claim 7 (depends on 1) The compressed composite of claim 1 wherein the dry bulk of the compressed product is less than 50% of the dry bulk of the components before the composite was compressed. ### Claim 8 (depends on 1) The compressed composite laminate of claim 1 wherein the superabsorbent material is present in an amount from about 200 percent to about 1,500 percent, dry weight, based on the dry weight of said fibrous web. ### Claim 9 An absorbent composite comprising: a first fibrous layer having a given thickness dimension in uncompressed form, superabsorbent material within said first layer and cooperating with the fibers of said first layer to retain said first layer in a compressed form with a thickness dimension less than said given thickness dimension; and a second layer discrete from but united to said first layer, said second layer having no superabsorbent material therewithin and being denser than said first layer prior to the incorporation of the superabsorbent therein, to provide preferential wicking of liquid within said second layer, whereby liquid wetted upon said composite in a given area is transported in said second layer away from said given area and distributed to portions of said first layer remote from said given area, said superabsorbent material upon swelling permitting said first fibrous layer to expand from said compressed form upon absorption of liquid in said superabsorbent material to thereby provide increased liquid holding capacity within said first layer. ### Claim 10 (depends on 9) The absorbent composite of claim 9 wherein said first fibrous layer comprises a nonwoven fibrous web. ### Claim 11 (depends on 10) The absorbent composite of claim 10 wherein said nonwoven fibrous web is comprised of polyester fibers. ### Claim 12 (depends on 9) The absorbent composite of claim 9 wherein the superabsorbent material is present in an amount from about 200 percent to about 1500 percent dry weight based on the dry weight of said fibrous first layer. ### Claim 13 (depends on 9) The absorbent composite of claim 9 wherein said second layer is comprised of chemically delignified wood pulp fibers. ### Claim 14 (depends on 9) The absorbent composite of claim 9 wherein said second layer is comprised of peat moss. ### Claim 15 (depends on 9) The absorbent composite of claim 9 wherein said second layer is comprised of rayon fibers. ### Claim 16 (depends on 9) The absorbent composite of claim 9 wherein said second layer is comprised of acrylic fibers. ### Claim 17 A disposable absorbent compressed composite comprising an absorbing layer, a transition zone, and a wicking layer, said absorbing layer comprising a fibrous web having a dry bulk recovery of at least about 30 percent, an initial dry bulk of at least about 40 cc/gm, a wet bulk of at least about 30 cc/gm and a weight of less than about 4 oz/yd.sup.2, said wicking layer comprising particles selected from the group consisting of cellulosic fibers, peat moss, rayon fibers, acrylic fibers, and mixtures thereof, some of said particles extending into and becoming integral with said absorbing layer to provide said transition zone, said absorbing layer having interspersed therein superabsorbent material present in an amount between about 200 percent and 1,500 percent dry weight basis based on said fibrous web dry weight basis, said composite in its compressed form. ### Claim 18 (depends on 17) The compressed composite of claim 17 wherein said fibrous web is comprised of a nonwoven fabric of synthetic staple fibers. ### Claim 19 (depends on 18) The compressed composite of claim 18 wherein the nonwoven fabric is comprised of polyester fibers. ### Claim 20 (depends on 17) The compressed composite of claim 17 wherein said wicking layer is comprised of chemically delignified wood pulp fibers. ### Claim 21 (depends on 17) The compressed composite of claim 17 wherein said wicking layer is comprised of peat moss. ### Claim 22 (depends on 17) The compressed composite of claim 17 wherein said wicking layer is comprised of acrylic fibers. ### Claim 23 (depends on 15) The compressed composite of claim 15 wherein said superabsorbent material is present in an amount from about 400 percent to about 1,200 percent dry weight basis based on said fibrous web dry weight basis. ### Claim 24 A disposable diaper containing an absorbent pad wherein said absorbent pad is an absorbent compressed composite comprising an absorbing layer, a transition zone, and a wicking layer, said absorbing layer comprising a fibrous web having a dry bulk recovery of at least about 30 percent, an initial dry bulk of at least about 40 cc/gm, a wet bulk of at least about 30 cc/gm and a weight of less than about 4 oz/yd.sup.2, said wicking layer comprising hydrophilic particles selected from the group consisting of cellulosic fibers, peat moss, rayon fibers, acrylic fibers, and mixtures thereof, some of said particles extending into and becoming integral with said absorbing layer to provide said transition zone, said absorbing layer having interspersed therein superabsorbent material present in an amount between about 200 percent and 1,500 percent dry weight basis based on said fibrous web dry weight basis, said composite in its compressed form having a dry bulk less than one-half the initial dry bulk of the components of said composite. ### Claim 25 (depends on 22) The disposable diaper of claim 22 wherein said absorbent pad is comprised of two or more absorbent compressed composites. ### Claim 26 (depends on 24) The disposable diaper of claim 24 wherein the absorbing layer of said compressed composite is comprised of a polyester nonwoven web and the wicking layer of said compressed composite is comprised of chemically delignified wood pulp fibers. ### Claim 27 (depends on 24) The disposable diaper of claim 24 wherein said compressed composite is comprised of an absorbing layer sandwiched between two wicking layers. ### Claim 28 A disposable diaper containing an absorbent pad wherein said absorbent pad is comprised of an absorbent composite comprising: a first fibrous layer having a given thickness dimension in uncompressed form, superabsorbent material within said first layer and cooperating with the fibers of said first layer to retain said first layer in a compressed form with a thickness dimension less than said given thickness dimension; and a second layer discrete from but united to said first layer, said second layer having no superabsorbent material therewithin and providing a higher capillary pressure than said first layer prior to the incorporation of the superabsorbent therein, to provide preferential wicking of liquid within said second layer, whereby liquid wetted upon said composite in a given area is transported in said second layer away from said given area and distributed to portions of said first layer remote from said given area, said superabsorbent material upon swelling permitting said first fibrous layer to expand from said compressed form upon absorption of liquid in said superabsorbent material to thereby provide increased liquid holding capacity within said first layer. ### Claim 29 A sanitary napkin containing an absorbent pad wherein said pad is comprised of an absorbent composite comprising a first layer, a second layer, and a transition zone integrally and intimately connecting said first and second layers, said first layer comprising a fibrous web having a dry bulk recovery of at least about 30 percent, an initial dry bulk of at least about 40 cc/gm, a wet bulk of at least about 30 cc/gm and a weight less than about 4 oz/yd.sup.2, and a plurality of particles of superabsorbent material disposed substantially throughout said first layer, said second layer comprising substantially uniformly disposed, hydrophilic particles selected from the group consisting of cellulosic fibers, peat moss, rayon fibers, acrylic fibers, and mixtures thereof, said particles being sufficiently closely spaced to adjacent particles to provide a capillary pressure to promote rapid movement of liquid along the plane of said layer, and said transition zone comprising portions of said hydrophilic particles extending into and becoming integral with said first layer with portions of said hydrophilic particles in intimate contact with said superabsorbent material, said composite in its compressed form having a dry bulk less than one-half the initial dry bulk of the components of said composite. ### Claim 30 (depends on 29) The sanitary napkin of claim 29 wherein said absorbent structure comprises two compressed composites superimposed one upon the other with the absorbing layers immediately adjacent one another. ### Claim 31 A sanitary napkin containing an absorbent structure, said absorbent structure being an absorbent composite comprising: a first fibrous layer having a given thickness dimension in uncompressed form, superabsorbent material within said first layer and cooperating with the fibers of said first layer to retain said first layer in a compressed form with a thickness dimension less than said given thickness dimension; and a second layer discrete from but united to said first layer, said second layer having no superabsorbent material therewithin and providing a higher capillary pressure than said first layer prior to the incorporation of the superabsorbent therein, to provide preferential wicking of liquid within said second layer, whereby liquid wetted upon said composite in a given area is transported in said second layer away from said given area and distributed to portions of said first layer remote from said given area, said superabsorbent material upon swelling permitting said first fibrous layer to expand from said compressed form upon absorption of liquid in said superabsorbent material to thereby provide increased liquid holding capacity within said first layer. ### Claim 32 A tampon having as its absorbent portion a disposable absorbent compressed composite comprising a first layer, a second layer, and a transition zone integrally and intimately connecting said first and second layers and being substantially coextensive therewith, said first layer comprising a fibrous web having a dry bulk recovery of at least about 30 percent, an initial dry bulk of at least about 40 cc/gm, a wet bulk of at least about 30 cc/gm and a weight less than about 4 oz/yd.sup.2, and a plurality of particles of superabsorbent material disposed substantially throughout said first layer, said second layer comprising substantially uniformly disposed, hydrophilic particles selected from the group consisting of cellulosic fibers, peat moss, rayon fibers, acrylic fibers, and mixtures thereof, said transition zone comprising portions of said hydrophilic particles extending into and becoming integral with said first layer with portions of said hydrophilic particles in intimate contact with said superabsorbent material, said composite in its compressed form having a dry bulk less than one-half the initial dry bulk of the components of said composite. ### Claim 33 (depends on 30) The tampon of claim 30 wherein said compressed composite is comprised of two wicking layers one on each side of an absorbing layer. ### Claim 34 A tampon containing an absorbent structure said absorbent structure being an absorbent composite comprising: a first fibrous layer having a given thickness dimension in uncompressed form, superabsorbent material within said first layer and cooperating with the fibers of said first layer to retain said first layer in a compressed form with a thickness dimension less than said given thickness dimension; and a second layer discrete from but united to said first layer, said second layer having no superabsorbent material therewithin and having a higher capillary pressure than said first layer prior to incorporation of the superabsorbent therein, to provide preferential wicking of liquid within said second layer, whereby liquid wetted upon said composite in a given area is transported in said second layer away from said given area and distributed to portions of said first layer remote from said given area, said superabsorbent material upon swelling permitting said first fibrous layer to expand from said compressed form upon absorption of liquid in said superabsorbent material to thereby provide increased liquid holding capacity within said first layer. ### Claim 35 A wipe comprising a nonwoven fabric as a substrate having affixed thereto a disposable absorbent compressed composite comprising a first layer, a second layer, and a transition zone integrally and intimately connecting said first and second layers said first layer comprising a fibrous web having a dry bulk recovery of at least about 30 percent, an initial dry bulk of at least about 40 cc/gm, a wet bulk of at least about 30 cc/gm, and a weight less than about 4 oz/yd.sup.2, and a plurality of particles of superabsorbent material disposed substantially throughout said first layer, said second layer comprising substantially uniformly randomly disposed, hydrophilic particles selected from the group consisting of cellulosic fibers, peat moss, rayon fibers, acrylic fibers and mixtures thereof, said particles being sufficiently closely spaced to adjacent particles to provide a higher capillary pressure to promote rapid movement of liquid along the plane of said layer, and said transition zone comprising portions of said hydrophilic particles extending into and becoming integral with said first layer with portions of said hydrophilic particles in intimate contact with said superabsorbent material, said composite in its compressed form having a dry bulk less than one-half the initial dry bulk of the components of said composite in an uncompressed form. ### Claim 36 A wipe comprising a nonwoven fabric having affixed thereto an absorbent composite comprising: a first fibrous layer having a given thickness dimension in uncompressed form, superabsorbent material within said first layer and cooperating with the fibers of said first layer to retain said first layer in a compressed form with a thickness dimension less than said given thickness dimension; and a second layer discrete from but united to said first layer, said second layer having no superabsorbent material therewithin and having a higher capillary pressure than said first layer prior to the incorporation of superabsorbent therein, to provide preferential wicking of liquid within said second layer, whereby liquid wetted upon said composite in a given area is transported in said second layer away from said given area and distributed to portions of said first layer remote from said given area, said superabsorbent material upon swelling permitting said first fibrous layer to expand from said compressed form upon absorption of liquid in said superabsorbent material to thereby provide increased liquid holding capacity within said first layer. ### Claim 37 A method for forming a disposable absorbent compressed composite comprising forming a fibrous web having a dry bulk recovery of at least about 30 percent, an initial dry bulk of at least about 40 cc/gm, a wet bulk of at least about 30 cc/gm and a weight of less than about 4 oz/yd.sup.2 ; interspersing therein superabsorbent material in an amount between about 200 percent and about 1,500 percent, dry weight basis, based on said fibrous web dry weight basis to form an absorbing layer; superposing thereon a wicking layer comprised of hydrophilic particles selected from the group consisting of cellulosic fibers, peat moss, rayon fibers, acrylic fibers, and mixtures thereof, and, compressing said layers sufficiently to reduce the dry bulk by at least 50 percent of the initial dry bulk of the components of said composite.