Deodorizing gas filter assembly for a body waste collection pouch, and method of making

1. A deodorizing flatus gas filter assembly for body waste collection pouches, comprising a filter pad having first and second filter layers of deodorizing filter media;

said layers being coextensive and superposed, with said filter layers having planar outer faces, opposed planar inner faces, and exposed peripheral edge surfaces;

and an imperforate gas and odor barrier layer sandwiched between said first and second filter layers for blocking the direct flow of gases between said opposed inner faces;

said assembly also including an envelope formed of liquid and gas impermeable material defining a chamber enclosing said pad;

said envelope having walls with first and second openings communicating with central portions of said first and second filter layers, respectively;

said pad having an outer surface sealed to one of the walls of the envelope;

said envelope defining a peripheral space about said pad to permit the flow of flatus gases from a peripheral edge surface of one of said filter layers to the peripheral edge surface of the other said filter layers;

whereby, flatus gases may enter said envelope through one of said envelope openings, enter one of said filter layers through said central portion of said outer face thereof, flow radially outwardly through said one filter layer to enter said peripheral space and then into the peripheral edge surface of the other of said filter layers to flow radially inwardly through said other of said filter layers and exit the assembly through the other of said envelope openings.

2. The filter assembly of claim 1 in which said outer faces of said first and second filter layers are each covered by a gas-impermeable film sealed thereto, each said film having a film opening in register with one of said envelope openings.

3. The filter assembly of claim 2 in which each of said films is sealed to a wall of said envelope about said registered openings of said film and envelope.

4. The filter assembly of claims 1 , 2 or 3 in which one of said walls of said envelope comprises the wall of a body waste collection pouch.

5. The filter assembly of claim 4 in which said assembly is located internally of said pouch.

6. The filter assembly of claim 4 in which said assembly is located externally of said pouch.

7. The filter assembly of claims 1 , 2 or 3 in which said imperforate gas and odor barrier layer comprises at least one barrier film.

8. The filter assembly of claim 7 in which said gas and odor barrier layer comprises two barrier films, one of which is sealed to the entire inner face of said first filter layer and the other of which is sealed to the entire inner face of said second filter layer.

9. The filter assembly of claims 1 , 2 or 3 in which at least one of said envelope openings has a gas-permeable liquid-resistant membrane formed of hydrophobic microporous material extending thereacross.

10. The filter assembly of claim 9 in which both of said envelope openings have gas-permeable liquid-resistant microporous membranes of hydrophobic material extending thereacross.

11. The filter assembly of claim 10 in which at least one of said membranes is formed of a material that is also oleophobic.

12. The filter assembly of claim 11 in which said assembly is located in a body waste collection pouch; said microporous membrane formed of a material that is also oleophobic being located within the interior of said pouch and said envelope opening across which said membrane extends being a flatus gas inlet opening.

13. The filter assembly of claims 1 , 2 or 3 in which said layers of said filter media have aligned central passages extending axially therethrough.

14. A body waste collection pouch having front and rear walls joined together along their peripheral edges;

said rear wall having a waste-receiving opening externally surrounded by attachment means for securing said pouch to a wearer;

a deodorizing flatus gas filter assembly within said pouch comprising a filter pad having first and second filter layer of deodorizing filter media;

said layers being coextensive and superposed, with said filter layers having planar outer faces, opposed planar inner faces, and exposed peripheral edge surfaces;

and an imperforate gas and odor barrier layer sandwiched between said first and second filter layers for blocking the direct flow of gases between said opposed inner faces;

said assembly also including an envelope formed of liquid and gas impermeable material defining a chamber enclosing said pad within said pouch;

said envelope having walls with first and second openings communicating with central portions of said outer faces of said first and second filter layers, respectively;

said pad having an outer surface sealed to one of the walls of the envelope;

said envelope defining a peripheral space about said pad to permit the flow of flatus gases from a peripheral edge surface of one of said filter layers to the peripheral edge surface of the other of said filter layers;

said first opening of said envelope constituting a flatus gas inlet opening for said assembly and said second opening constituting an outlet opening;

said outlet opening communicating externally of said pouch.

15. The pouch of claim 14 in which said wall of said envelope having said outlet opening comprises a wall of said pouch.

16. The pouch of claim 14 in which said wall of said envelope having said outlet opening is sealed to one of said walls of said pouch within said pouch chamber; said one wall of said pouch having a vent opening communicating with said outlet opening.

17. The pouch of claims 14 , 15 or 16 in which said outer faces of said first and second filter layers are each covered by a gas-impermeable film sealed thereto, each said film having a film opening in register with one of said envelope openings.

18. The pouch of claim 17 in which each of said films is sealed to a wall of said envelope about said registered openings of said films and envelope.

19. The pouch of claims 14 , 15 or 16 in which said imperforate gas and odor barrier layer comprises at least one barrier film.

20. The pouch of claim 19 in which said gas and odor barrier layer comprises two barrier films, one of which is sealed to the entire inner face of said first filter layer and the other of which is sealed to the entire inner face of said second filter layer.

21. The pouch of claims 14 , 15 or 16 in which at least one of said envelope openings has a gas-permeable liquid-resistant membrane formed of hydrophobic microporous material extending thereacross.

22. The pouch of claim 21 in which both of said envelope openings has a gas-permeable liquid-resistant of hydrophobic microporous material extending thereacross.

23. The pouch of claim 22 in which at least one of said membranes is formed of a material that is also oleophobic.

24. The pouch of claims 14 , 15 or 16 in which each of said layers of said filter media has a central passage extending axially therethrough.

25. A method of making a deodorizing gas filter assembly for body waste collection pouches, comprising the steps of

forming a laminated sheet having a porous core layer of activated carbon particles disposed between first and second skin layers of liquid and gas impermeable film;

said sheet defining in outline a pair of sections on each side of a transverse midline;

said first skin layer having a pair of vent apertures, each located in a central portion of each said section;

securing a gas-permeable but liquid-resistant microporous membrane over each of said vent apertures;

cutting said sheet along said transverse midline through at least said first skin layer and through said core layer;

then arranging said sections so that the second skin layer components of each are disposed in facing relation, thereby forming a filter sandwich with the second skin layer components of said sections located between the core layers components of said sections which in turn are covered by apertured first skin layers components of said sections;

and then enclosing said filter sandwich in a gas-impermeable envelope having a pair of side walls with openings in register with and sealed about each of said apertures, said envelope defining a peripheral space extending about peripheral edge surfaces of the filter sandwich.

26. The method of claim 25 in which said enclosing step includes locating said envelope within a body waste collection pouch having a gas discharge opening in a wall thereof with one of said envelope openings of said envelope being aligned with a gas discharge vent opening of said pouch.

27. The method of claim 25 in which one of said walls of said envelope comprises a wall of a body waste collection pouch having a gas discharge vent opening aligned with and sealed about one of said apertures of said filter sandwich.

28. The method of claim 27 in which said enclosing step includes locating said filter sandwich within the interior of said body waste collection pouch.

29. The method of claim 25 in which said skin layers are formed of flexible polymeric film and said cutting step comprises cutting through only said first skin layer and said core layer, leaving a portion of said second skin layer along said midline as a living hinge.

30. The method of claim 29 in which said arranging step includes folding said filter sandwich at said living hinge to bring said first skin layer components of said sections into facing relation.

31. The method of claim 25 in which said enclosing step includes leaving a peripheral space within said envelope about said filter sandwich.

32. The method of claim 25 in which said sheet is generally rectangular and in which said two sections on opposite sides of said midline are each of equal area and of generally rectangular shape.