Method of assembling a filter holder

Claim 1

A method of assembling a membrane filter holder having a filter assembly and enclosing means, the filter assembly comprising a membrane constructed of flat plastic sheet material, said membrane having a flat upper surface and a flat lower surface, substantially all of said lower surface contacting a flat porous metal support plate, and the enclosing means comprising an upper enclosure and a lower enclosure, said enclosures having opposed central recess portions and opposed sealing portions completely surrounding said central recessed portions, the upper closure having a shelf about the inside edge of said recessed portion and having an inlet aperture, said lower enclosure having an outlet aperture, said method comprising the steps of: (a) aligning said upper enclosure and said lower enclosure on opposite sides of said filter assembly with an edge strip of the upper flat surface of said membrane contacting said shelf and said opposed sealing portions contacting each other and the periphery of said support plate; (b) heating said metal support plate by induction heating, thereby heating said membrane to a temperature sufficient to melt said upper enclosure at said shelf; and (c) maintaining contact between said shelf and said edge strip until said edge strip is sealed continuously to said shelf, wherein said induction heating further raises the temperature of said metal support plate above the melting temperature of said opposed sealing portions, thereby causing said upper enclosure and said lower enclosure to form a fused seal at the contact point of said sealing portions adjacent said metal support plate.

Claim 2

A method of assembling a membrane filter holder having a filter assembly and enclosing means, the filter assembly comprising a membrane constructed of flat plastic sheet material, said membrane having a flat upper surface and a flat lower surface, substantially all of said lower surface contacting a flat porous metal support plate, and the enclosing means comprising an upper enclosure and a lower enclosure, said enclosures having opposed central recess portions and opposed sealing portions completely surrounding said central recessed portions, the upper closure having a shelf about the inside edge of said recessed portion and having an inlet aperture, said lower enclosure having an outlet aperture, said method comprising the steps of: (a) aligning said upper enclosure and said lower enclosure on opposite sides of said filter assembly with an edge strip of the upper flat surface of said membrane contacting said shelf and said opposed sealing portions contacting each other and the periphery of said support plate; (b) heating said metal support plate by induction heating, thereby heating said membrane to a temperature sufficient to melt said upper enclosure at said shelf; and (c) maintaining contact between said shelf and said edge strip until said edge strip is sealed continuously to said shelf, wherein said induction heating further raises the temperature of said metal support plate above the melting temperature of said opposed sealing portions, thereby causing said upper enclosure and said lower enclosure to form a fused seal at the contact point of said sealing portions adjacent said metal support plate.