Enclosure ventilation filter and assembly method
A filter assembly for an enclosure, particularly for an ostomy bag, is described having an enclosure side, a first layer which is gas permeable, and an adsorbent layer comprising adsorbent particles dispersed in a fine fiber web. The enclosure side of the filter assembly includes an adhesive zone in which adhesive is present having an outer adhesive perimeter and a weld area surrounding at least a portion of the adhesive zone, where the filter assembly is heat-sealable to the enclosure at the weld area. A method of assembly is also described.
1. A filter assembly for an enclosure, comprising:
an enclosure side and a side opposite from the enclosure side;
a first layer which is gas permeable; and
an adsorbent layer comprising adsorbent particles;
wherein the enclosure side of the filter assembly comprises:
an adhesive zone in which adhesive is present having an outer adhesive perimeter;
a weld area surrounding at least a portion of the adhesive zone, where the filter assembly is heat-sealable to the enclosure at the weld area.
2. The filter assembly of claim 1 , wherein the adhesive zone has an inner adhesive perimeter that defines an exit window portion that is completely surrounded by the adhesive zone.
3. The filter assembly of claim 2 , wherein the weld area completely surrounds the adhesive zone.
4. The filter assembly of claim 3 , wherein the adhesive zone is a first sealing zone and the weld area is a second sealing zone.
5. The filter assembly of claim 3 , wherein the first layer is sealed to the enclosure at the weld area.
6. The filter assembly of claim 5 , wherein the enclosure is a flexible bag comprising plastic.
7. The filter assembly of claim 3 , wherein the weld area is adjacent to the adhesive zone along the outer adhesive perimeter.
8. The filter assembly of claim 1 , wherein the first layer is microporous.
9. The filter assembly of claim 1 , wherein the adsorbent layer comprises activated carbon and is substantially free of binder material.
10. The filter assembly of claim 1 , wherein the adsorbent layer comprises about 1 to 30 weight percent fine fiber having a fiber diameter of about 0.001 to 5 micron and 70 to 99 weight percent adsorbent particles.
11. The filter assembly of claim 1 further comprising a second layer that is gas permeable and liquid impermeable, wherein the adsorbent layer is sandwiched between the first layer and the second layer.