Absorbent product including super absorbent material and a fluid absorption capacity monitor

• US 5,354,289 A
• Filed: 07/23/1993
• Issued: 10/11/1994
• Est. Priority Date: 07/23/1993
• Status: Expired due to Term

• Current Assignee: Carol M. Stocking
• Original Assignee: Principle Business Enterprises Incorporated
• Inventors: Mitchell, Winalee G., Plotka, Michael, Szypka, Andrew J.
• Primary Examiner(s): Green, Randall L.
• Assistant Examiner(s): ZUTTARELLI, ANTHONY
• Application Number:
  US08/096,552
• Time in Patent Office: 445 Days
• Field of Search: 604/358, 604/361, 604/362, 604/368, 604/385.1
• US Class Current: 604/361
• CPC Class Codes: A61F 13/42 with wetness indicator or alarm
• CPC Class Codes: A61F 2013/426 Moisture sensitive polymers

Abstract

A capacity monitor for diapers and the like, including super absorbent material disposed in or adjacent to an absorbent core is disclosed. The monitor comprises an indicator and a baffle to prevent direct contact between the absorbent core and the indicator. The indicator is preferably a ribbon of hot melt adhesive with a wetness indicator which changes color when exposed to liquid. The baffle is a substantially water impervious sheet positioned between the absorbent core and the indicator so as to prevent direct contact between them. The diaper and the monitor are constructed so that there is a threshold level of liquid which, when deposited in the diaper, will effect a color change in the indicator. A quantity of liquid which is below the threshold will not effect a color change in the indicator and a quantity of liquid which is above the threshold will effect a color change in the indicator. In the latter case, the indicator will change color over a portion of its length which is proportional to the quantity of deposited liquid which exceeds the threshold amount. The threshold is preferably at least twenty percent of the in-situ capacity of the super absorbent material in the diaper. In a diaper comprising an absorbent core, a backing sheet and a cover sheet, the monitor is positioned between the absorbent core and the backing sheet and, preferably, a strip of non-woven material is positioned between the monitor and the backing sheet to prevent sticking.

Claims

1. A diaper including a capacity monitor, said diaper comprising an absorbent core including super absorbent material, a hydrophilic cover sheet and a water impervious, translucent or transparent backing sheet, said core being positioned between said cover sheet and said backing sheet and said super absorbent material in said diaper having a given in-situ capacity for synthetic urine, said capacity monitor comprising

an indicator extending longitudinally a substantial distance, said indicator being operable to provide a visually perceptible change when wet, said indicator being positioned in said diaper adjacent to said backing sheet so that the change of the indicator is visually perceptible through said sheet and

a substantially water impervious baffle positioned inside the diaper between said backing sheet and said absorbent core so as to cover said indicator and separate it from said absorbent core, said baffle having a width which is greater than that of said indicator and a free edge around which synthetic urine can migrate from said absorbent core to said indicator, said baffle being operable to prevent the flow of synthetic urine into wetting relationship with said indicator when the diaper contains an amount of synthetic urine which is less than a given percent of the in-situ capacity of the super absorbent, and ineffective to prevent such flow when the diaper contains an amount of synthetic urine which is greater than the given percent of the in situ capacity of the super absorbent, the given percent being at least 20.

2. The diaper claimed in claim 1 which additionally includes

indicia provided on said diaper and visible through said backing sheet, said indicia being operable to indicate a predetermined length of said indicator which undergoes a visually perceptible change when a quantity of synthetic urine approximately equal to the in-situ capacity of the super absorbent has been deposited on the diaper.

3. The diaper claimed in claim 1 or 2 wherein the given percent exceeds thirty percent of the in-situ capacity of the super absorbent in the diaper.

4. The diaper claimed in claim 1 or 2 wherein the given percent exceeds forty percent of the in-situ capacity of the super absorbent in the diaper.

12. The diaper claimed in claim 1, 5 or 9 which further comprises a strip of non-woven material positioned between said indicator and said backing sheet, said strip of non-woven material being hydrophilic and being operable to prevent sticking between said indicator and said backing sheet so that synthetic urine is able to migrate from said absorbent core to said indicator.

5. A diaper including a capacity monitor, said diaper comprising an absorbent core comprising a fluff component and a super absorbent component, a hydrophilic cover sheet and a water impervious, translucent or transparent backing sheet, said core being positioned between said cover sheet and said backing sheet and said super absorbent material in said diaper having a given in-situ capacity for synthetic urine, said capacity monitor comprising

an indicator extending longitudinally a substantial distance, said indicator being operable to provide a visually perceptible change when wet, said indicator being positioned in said diaper adjacent to said backing sheet so that the change of the indicator is visually perceptible through said backing sheet and

a substantially water impervious baffle positioned inside the diaper between said backing sheet and said absorbent core so as to cover said indicator and separate it from said absorbent core, said baffle having a width which is greater than that of said indicator and a free edge around which synthetic urine can migrate from said absorbent core to said indicator, said baffle being effective, in cooperation with the components of the diaper, to prevent the flow of synthetic urine into wetting relationship with said indicator when the diaper contains an amount of synthetic urine which is less than a given percent of the in-situ capacity of the super absorbent, and ineffective to prevent such flow when the diaper contains an amount of synthetic urine which is greater than the given percent of the in situ capacity of the super absorbent, the given percent being at least 20.

6. The diaper claimed in claim 5 which additionally includes

indicia provided on said diaper and visible through said backing sheet, said indicia being operable to indicate a predetermined length of said indicator which undergoes a visually perceptible change when a quantity of synthetic urine approximately equal to the in-situ capacity of the super absorbent has been deposited on the diaper.

7. The diaper claimed in claim 5 or 6 wherein the given percent exceeds thirty percent of the in-situ capacity of the super absorbent in the diaper.

8. The diaper claimed in claim 5 or 6 wherein the given percent exceeds forty percent of the in-situ capacity of the super absorbent in the diaper.

9. A diaper including a capacity monitor, said diaper comprising an absorbent core including a fluff component and a super absorbent component, a hydrophilic cover sheet and a water impervious, translucent or transparent backing sheet, said core being positioned between said cover sheet and said backing sheet and said super absorbent material in said diaper being operable to absorb up to a given, maximum quantity of a desired liquid to the extent that, ten minutes after deposition of said given amount of liquid, said diaper has a skin wetness number of substantially zero, said capacity monitor comprising

a hot melt adhesive containing a color change indicator, and extending longitudinally a substantial distance, said indicator being operable to provide a visually perceptible color change when said hot melt adhesive is wet, said hot melt adhesive being positioned in said diaper adjacent to said backing sheet so that the change of color of the indicator is visually perceptible through said backing sheet and

a substantially water impervious baffle positioned inside the diaper between said backing sheet and said absorbent core so as to cover said hot melt adhesive and separate it from said absorbent core, said baffle having a width which is greater than that of said hot melt adhesive and a free edge around which liquid can migrate from said absorbent core to said hot melt adhesive, said baffle cooperating with the components of the diaper to control the migration of liquid from said at least one absorbent component to said indicator so that said given quantity of desired liquid deposited on the diaper produces a visually perceptible change over a predetermined length of said indicator and

indicia provided on said diaper and visible through said backing sheet, said indicia being operable to indicate the predetermined length of said hot melt adhesive which undergoes a visually perceptible change when said given quantity of desired liquid is deposited on the diaper.

10. An absorbent product including a capacity monitor, said product comprising an absorbent core including super absorbent material, said core having a first and a second side, and a water impervious, translucent or transparent backing sheet, said backing sheet being positioned adjacent to said first side of said core and said super absorbent material in said absorbent product having a given in-situ capacity for liquid, said capacity monitor comprising

an indicator extending longitudinally a substantial distance, said indicator being operable to provide a visually perceptible change when wet, said indicator being positioned in said absorbent product between said backing sheet and said core so that the change of the indicator is visually perceptible through said backing sheet and

a substantially water impervious baffle positioned inside the diaper between said backing sheet and said absorbent core so as to cover said indicator and separate it from said absorbent core, said baffle having a width which is greater than that of said indicator and a free edge around which liquid can migrate from said absorbent core to said indicator, said baffle being operable to prevent the flow of a liquid into wetting relationship with said indicator when the core contains an amount of the liquid which is less than a given percent of the in-situ capacity of the super absorbent, and ineffective to prevent such flow when the core contains an amount of the liquid which is greater than the given percent of the in situ capacity of the super absorbent, the given percent being at least 20.

11. The absorbent product claimed in claim 10 which further comprises a strip of non-woven material positioned between said indicator and said backing sheet, said strip of non-woven material being hydrophilic and being operable to prevent sticking between said indicator and said backing sheet so that liquid is able to migrate from said absorbent core to said indicator.