Absorbent core for absorbing body liquids and method

• US 5,938,650 A
• Filed: 07/29/1996
• Issued: 08/17/1999
• Est. Priority Date: 08/09/1995
• Status: Expired due to Term

• Current Assignee: FiberTech Group, Inc. (Berry Global Group Inc.)
• Original Assignee: FiberTech Group, Inc. (Berry Global Group Inc.)
• Inventors: Baer, Samuel C., Boehmer, Brian E., Bononcini, Kenneth
• Primary Examiner(s): Clarke, Robert A.
• Application Number:
  US08/681,665
• Time in Patent Office: 1,114 Days
• Field of Search: 604/358, 604/366, 604/368, 604/372, 604/370, 604/378-380, 604/385.1
• US Class Current: 604/368
• CPC Class Codes: A61F 13/5323 having absorbent material located in discrete regions, e.g. pockets

Abstract

The disclosure describes an absorbent core, free of wood pulp or other cellulosic materials. The core includes two thin outer layers, with at least one layer being porous and receptive to body liquids. A quantity of superabsorbent polymer particles of a particular type is provided between the outer layers and is loosely contained in individual unbonded open zones or flat closed pockets defined by a plurality of intersecting heat bond lines between the layers, with the lines defining a densified and a hot calendar-bonded fiber structure to provided wicking lines or flow zones between the pockets. The dry product is a flat, thin partial laminate.

Claims

1. A core for the absorption of liquids, said core consisting essentially of a pair of outer flat nonwoven porous fabric layers of thermoplastic fibers, each of said layers having a dry basis weight of from about 17.5 to 25 grams per square meter, said outer flat layers being heat sealed together along a plurality of intersecting lines to define a plurality of flat, closed, porous pockets, with said intersecting seal lines defining flow channels between pockets, and between 45 to 250 grams per square meter of liquid superabsorbing polymer in dry particulate form loosely contained in said closed pockets, said superabsorbing polymer being of the type in which the particles swell and remain as individual particles upon exposure to liquid, said core having a thickness of less than 7 mm in dry form, the contained superabsorbing polymer, after being exposed to liquid passing through said porous layers, swelling substantially to swell said pockets with said core defining a three dimensional bubble-like structure.

2. The core of claim 1 wherein said core comprises opposed parallel edges, and said intersecting seal lines comprise lines extending parallel to said edges.

3. The core of claim 1 wherein said outer layers comprise nonwoven fabric of polypropylene fibers.

4. A core for the absorption of liquids, said core consisting essentially of a pair of superimposed outer flat containment layers of thermoplastic materials, each of said outer containment layers having a dry basis weight of from about 17.5 to 25 grams per square meter and at least one outer containment layer being a porous nonwoven fabric comprising thermoplastic layers, a continuous intersecting gridwork of heat bond lines formed between said outer containment layers and defining a plurality of individual closed pockets in dry form, and between 45 to 250 grams per square meter of superabsorbing polymer particles loosely contained in said pockets, said pockets being free of cellulose pulp, the thickness of said the core in the dry condition being less than 7 mm and having a total basis weight of 80 to 300 grams per square meter said supersabsorbing polymer, when exposed to liquid, swelling to cause said pockets to enlarge and form a three dimensional bubble-like structure.

5. An absorbent structure core consisting essentially of a pair of flat layers, each of said layers having a dry basis weight of about 17.5 to 25 grams per square meter and at least one of said layers being porous to transfer of liquids, a plurality of permanent bonds between said layers defining a plurality of closed flat pockets and a plurality of permanent intersecting flow channels between said pockets, from about 45 to about 250 gsm of particles of a superabsorbing polymer disposed in said flat pockets, said core having a thickness of less than 7 mm on a dry basis and a total basis weight of from about 80 to about 300 gsm.

6. A combination including a core for the absorption of liquids and an acquisition layer, said core consisting essentially of a pair of outer flat nonwoven porous fabric layers of thermoplastic fibers, each of said layers having a dry basis weight of from about 17.5 to 25 grams per square meter, said outer flat layers being heat sealed together along a plurality of intersecting lines to define a plurality of flat, closed, porous pockets, with said intersecting seal lines defining flow channels between pockets, and between 45 to 250 grams per square meter of liquid superabsorbing polymer in dry particulate form loosely contained in said closed pockets, said superabsorbing polymer being of the type in which the particles swell and remain as individual particles upon exposure to liquid, said core having a thickness of less than 7 mm in dry form, the contained superabsorbing polymer, after being exposed to liquid passing through said porous layers, swelling substantially to swell said pockets with said core defining a three dimensional bubble-like structure, said core being in combination with said acquisition layer comprising a lower density nonwoven fabric layer in contact with one of said layers of nonwoven thermoplastic fibers for improving distribution of said liquid to said core.