Diapers with moisture detection and process and apparatus for making them

• US 6,200,250 B1
• Filed: 03/23/1998
• Issued: 03/13/2001
• Est. Priority Date: 05/07/1996
• Status: Expired due to Fees

• Current Assignee: Knox Security Engineering Corp.
• Original Assignee: Knox Security Engineering Corp.
• Inventors: Janszen, David
• Primary Examiner(s): Johnson, Brian L.
• Assistant Examiner(s): LUBY, MATTHEW D
• Application Number:
  US09/046,468
• Time in Patent Office: 1,086 Days
• Field of Search: 493/328, 493/334, 493/374, 493/383, 493/379, 493/938, 604/358, 604/361
• US Class Current: 493/383
• CPC Class Codes: A61F 13/42 with wetness indicator or alarm
• CPC Class Codes: Y10S 493/938 Apparel

Abstract

A method of manufacturing a diaper includes constructing a backing sheet having an exterior surface and an interior surface so a to form an exterior of the diaper and an interior of the diaper, bonding a tissue layer to the interior surface of the backing sheet, bonding an elastic pouch to the exterior surface of the backing sheet to contain a detector module, and placing sensing electrodes within the interior of the diaper along the interior surface of the backing sheet in contact with the tissue layer that is bonded to the backing sheet, and in a direction to extend opposite the elastic pouch that is bonded to the outside of the backing sheet so as to allow the sensing electrodes to couple capacitively to the sensor module.

Claims

1. A method of manufacturing a diaper, comprising:

forming a liquid-impermeable backing sheet having an exterior surface and an interior surface so as to form an exterior of the diaper and an interior of the diaper;

bonding a liquid-absorbing arrangement to the interior surface of the backing sheet;

bonding an elastic pocket to the exterior surface of the backing sheet to contain a detector module;

placing sensing electrodes within the interior of the diaper and within the interior surface of the backing sheet in contact with the liquid absorbing arrangement that is bonded to the backing sheet, and in a direction to extend opposite the elastic pocket that is bonded to the exterior surface of the backing sheet so as to allow the sensing electrodes to couple only capacitively to the detector module.

2. A method as in claim 1, wherein bonding of the liquid absorbing arrangement includes placing a wetness-absorbing core layer on the liquid-impermeable backing sheet and placing a liquid-permeable film layer on the wetness-absorbing core layer.

3. A method as in claim 1, wherein placing the sensing electrodes includes bonding coupling electrodes forming a part of the sensing electrodes and having widened conductive areas on the ends of the sensing electrodes against the interior surface of the backing sheet opposite the elastic pocket.

4. A method as in claim 2, wherein bonding of the liquid absorbing arrangement includes placing a wetness distributing tissue layer between the liquid-impermeable backing sheet and the wetness-absorbing core layer and over the sensing electrodes.

5. A method as in claim 1, wherein bonding of the liquid absorbing arrangement includes placing a wetness-impermeable barrier between portions of the sensing electrodes and the core wetness-absorbing layer to define parts of the electrodes to be subject to contact with liquid.

6. A method as in claim 3, wherein placing sensing electrodes within the interior of the diaper and within the interior surface of the backing sheet includes assembling the sensing electrodes and the coupling electrodes with a sensor carrier and bonding the sensor carrier to the backing sheet.

7. A method as in claim 1, wherein placing sensing electrodes within the interior of the diaper and within the interior surface of the backing sheet includes forming pluralities of pairs of sensing electrodes in a continuous line and separating the pairs of sensing electrodes from the other pairs before placing each pair of sensing electrodes in a diaper.

8. A method as in claim 1, wherein placing sensing electrodes within the interior of the diaper and within the interior surface of the backing sheet includes forming the sensing electrodes by selective removal of continuous conductive coating or converted outer layer from surface of a film material to render multiple isolated conductive areas from a continuous piece of coated film.

9. A method as in claim 1, wherein placing sensing electrodes within the interior of the diaper and within the interior surface of the backing sheet includes forming each sensing electrode from a plurality of parallel filamentary elements.

10. A method as in claim 1, wherein placing sensing electrodes within the interior of the diaper and within the interior surface of the backing sheet includes forming the sensing electrodes of filamentary elements in contact with flat conductors forming the coupling electrodes nipped down against the sensing electrode with the tissue layer nipped down over said sensing and said coupling electrodes and the core layer nipped down over the tissue layer and the tissue layer nipped down over the core layer.

11. A method as in claim 1, wherein placing sensing electrodes includes placing an electrically conductive material in spaces adjacent the sensing electrodes.

12. A method as in claim 1, wherein placing sensing electrodes within the interior of the diaper and within the interior surface of the backing sheet includes incorporating the sensing electrodes within the liquid absorbing arrangement.

13. A method as in claim 2, wherein placing sensing electrodes within the interior of the diaper and within the interior surface of the backing sheet includes incorporating the sensing electrodes within the wetness-absorbing core layer and extending the ends of the electrodes outside of the wetness absorbing core layer between the wetness-absorbing core layer and the liquid-impermeable backing sheet.

14. A method as in claim 1, wherein placing sensing electrodes within the interior of the diaper and within the interior surface of the backing sheet includes forming the sensing electrodes by abrading portions of a conductive layer from a ribbon of non-conductive material carrying a conductive layer.

15. A method as in claim 1, wherein placing sensing electrodes within the interior of the diaper and within the interior surface of the liquid-impermeable backing sheet includes forming the sensing electrodes by placing conductive filaments on an adhesive on a backing layer.

16. A method as in claim 1, wherein placing sensing electrodes within the interior of the diaper and within the interior surface of the backing sheet includes forming the sensing electrodes by spin wrapping wire about a yarn.

17. A method as in claim 1, wherein forming the backing sheet includes forming the backing sheet from two overlying bonded components and treating a portion at the pocket to make the portion at the pocket thinner than the remainder of the backing sheet.

18. A method as in claim 17, wherein treating a portion of the backing sheet at the pocket includes ultrasonic treatment.