Abstract: A filter assembly, particularly for use with a plastic bottle having an open neck with an inside diameter of about 50 mm or less (e.g. about 25 mm), includes a tube of filtering material connected to one surface of a cap while a valve extends from an opposite surface of the cap. The tube is preferably of filtering material such as activated carbon with plastic binder, having a substantially continuous liquid-porous sidewall, a hollow interior, a first closed end, and a second open end. The tube is operatively connected to the cap second surface at the tube second open end by sonic welding, a mechanical connection, or adhesively. The cap has a fitting portion for cooperating with the bottle neck, such as internal screw threads or a snap portion. The valve may be a reciprocating valve, a baby bottle nipple, or a spray device. A biocidal medium may be disposed within the hollow interior of the filter tube, and the tube may be wrapped with a filter material having a pore size of about 1-4 microns.

Abstract: A filter assembly, particularly for use with a plastic bottle having an open neck with an inside diameter of about 50 mm or less (e.g. about 25 mm), includes a tube of filtering material connected to one surface of a cap while a valve extends from an opposite surface of the cap. The tube is preferably of filtering material such as activated carbon with plastic binder, having a substantially continuous liquid-porous sidewall, a hollow interior, a first closed end, and a second open end. The tube is operatively connected to the cap second surface at the tube second open end by sonic welding, a mechanical connection, or adhesively. The cap has a fitting portion for cooperating with the bottle neck, such as internal screw threads or a snap portion. The valve may be a reciprocating valve, a baby bottle nipple, or a spray device. A biocidal medium may be disposed within the hollow interior of the filter tube, and the tube may be wrapped with a filter material having a pore size of about 1-4 microns.