A process for the manufacture of intravenous solution filter units includes injection molding a sealing member onto the periphery of the assembled filter components to hermetically seal the components into an integral assembly. The filter unit itself includes a housing and a filter element disposed internally thereof. The filter element is supported by a grid having a design and placement within the housing to assure, in conjunction with other structural features of the filter, the complete purging of gases from the filtrate. Also disclosed is a method for hermetically sealing the filter element to its thermoplastic support which provides an improved seal which will not leak. This method comprises the molding of the support, the alignment of the filter element on the support, the application of pressure to hold the element on the support and the overmolding of the periphery of the element to seal the edge of the element to the support.