Pre-form for exhaust aftertreatment control filter

A green uncured pre-form for an exhaust aftertreatment filter, said pre-form comprising first and second sheets of regenerable filter media, said second sheet having a plurality of pleats defined by wall segments extending in zig-zag manner between pleat tips at axially extending bend lines, the pleat tips on one side of said second sheet being in contiguous relation with said first sheet, said flow channels having a lateral cross-sectional shape comprising two adjacent included angles each greater than 45° and less than 75°, wherein said two adjacent included angles comprise a first angle between said first sheet and a first said wall segment of said second sheet, and a second angle between first sheet and a second said wall segment of said second sheet, each of said first and second angles being greater than 45° and less than 75°, said lateral cross-sectional shape of said flow channels consists of three pleat tips and three included angles, namely said first angle, said second angle, and a third angle between said first and second wall segments, and said lateral cross-sectional shape is an isosceles triangle and wherein 45 ∘ < θ < 75 ∘ 0.5 ⁢ ⁢ mm < 2 ⁢ b · sin ⁢ 1 2 ⁢ θ · cos ⁢ 1 2 ⁢ θ 1 + sin ⁢ 1 2 ⁢ θ < 2.9 ⁢ ⁢ mm

• where θ is said third angle between said first and second wall segments, and b is the length of each of said first and second wall segments.

A green uncured pre-form for an exhaust aftertreatment filter, said pre-form comprising first and second sheets of regenerable filter media, said second sheet having a plurality of pleats defined by wall segments extending in zig-zag manner between pleat tips at axially extending bend lines, the pleat tips on one side of said second sheet being in contiguous relation with said first sheet, said flow channels having a lateral cross-sectional shape comprising two adjacent included angles each greater than 45° and less than 75°, wherein said two adjacent included angles comprise a first angle between said first sheet and a first said wall segment of said second sheet, and a second angle between first sheet and a second said wall segment of said second sheet, each of said first and second angles being greater than 45° and less than 75°, and said lateral cross-sectional shape of said flow channels consists of four pleat tips and four included angles.

A method of making a green uncured pre-form for an exhaust aftertreatment filter, comprising providing first and second sheets of regenerable filter material, forming a plurality of pleats in said second sheet defined by wall segments extending in zig-zag manner between pleat tips at axially extending bend lines, bonding the pleat tips on one side of said second sheet to said first sheet to define axial flow channels, forming said flow channels having a lateral cross-sectional shape comprising two adjacent included angles greater than 45° and less than 75°, and providing said wall segments with a thickness less than 0.8 mm, a porosity greater than 80%, and an extension between pleat tips less than 10 mm.

A method of making a green uncured pre-form for an exhaust aftertreatment filter, comprising providing first and second sheets of regenerable filter material, forming a plurality of pleats in said second sheet defined by wall segments extending in zig-zag manner between pleat tips at axially extending bend lines, bonding the pleat tips on one side of said second sheet to said first sheet to define axial flow channels, forming said flow channels having a lateral cross-sectional shape comprising two adjacent included angles greater than 45° and less than 75° wherein each of said sheets comprises 50% to 80% by weight ceramic fibers, 10% to 50% by weight organic fibers, and 2% to 20% by weight thermoplastic resin.

A method of making a green uncured pre-form for an exhaust aftertreatment filter, comprising providing first and second sheets of regenerable filter material, forming a plurality of pleats in said second sheet defined by wall segments extending in zig-zag manner between pleat tips at axially extending bend lines, bonding the pleat tips on one side of said second sheet to said first sheet to define axial flow channels, forming said flow channels having a lateral cross-sectional shape comprising two adjacent included angles greater than 45° and less than 75°, wherein each of said first and second sheets has a porosity of 80% to 95% and a mean flow pore diameter of 5 to 15 microns.