Air filter for workstations and methods of making and using such air filter

Claim 1

A filter apparatus for providing a clean environment at a workstation, comprising a frame and a filter unit mounted in said frame, said filter unit including a first sheet of filter material folded in a zig-zag configuration to form alternating open portions and apex portions at air inlet and outlet sides of said folded sheet material, said apex portions at said air outlet side of said folded first sheet lying substantially in a common plane, and a second sheet of air permeable fine mesh material, said second sheet including a planar section extending across said apex portions of said air outlet side of said folded sheet material for establishing an even flow of air exiting the filter apparatus, wherein said second sheet includes peripheral portions folded against the lateral edges of said first sheet.

Claim 10

A method of forming a filter comprising the steps of: A) folding a first sheet of filter material in a zig-zag manner with the fold lines thereof extending from one lateral edge of said sheet to the other lateral edge, B) bonding the folds of said first sheet together to retain said first sheet in a zig-zag folded state, C) bonding a substantially planar second sheet of air permeable material against the fold lines on one side of said first sheet, said second sheet sized to provide laterally projecting portions which project laterally beyond said lateral edges of said first sheet by a distance at least substantially equal to a height of said lateral edges, D) folding said laterally projecting portions against said lateral edges of said first sheet to cover said lateral edges, and bonding said folded laterally projecting portions to said lateral edges, E) placing a unit comprised of said first and second sheets into a substantially planar frame, and bonding to said frame a surface of each of said projecting portions which faces away from said first sheet, and F) bonding said unit to said frame.

Claim 11

A method of forming a filter comprising the steps of: A) folding a first sheet of filter material in a zig-zag manner with the fold lines thereof extending from one lateral edge of said sheet to the other lateral edge, B) bonding the folds of said first sheet together to retain said first sheet in a zig-zag folded state, C) bonding a substantially planar second sheet of air permeable material against the fold lines on one side of said first sheet, said second sheet sized to provide laterally projecting portions which project laterally beyond said lateral edges of said first sheet by a distance at least substantially equal to a height of said lateral edges, D) folding said laterally projecting portions against said lateral edges of said first sheet to cover said lateral edges, and bonding said folded laterally projecting portions to said lateral edges, E) placing a unit comprised of said first and second sheets into a substantially planar frame, and bonding to said frame a surface of each of said projecting portions which faces away from said first sheet, and F) bonding said unit to said frame.