| abstract |
A gas mask filter canister of varying shapes is filled by orienting the a fill opening to face upwardly, introducing into the fill opening a particulate filter material, and vibrating the filter canister at a frequency and amplitude, and for a time until a predetermined packing density is reached. The invention can be used to fill elliptical or other odd shaped filter canisters having a concave profiles to conform closely to the curvature of the wearer's face. |