Apparatus And Method Of Producing Insulation Preform With Graded Porosity

An insulation preform having graded porosity for an exhaust treatment system of a vehicle, the insulation preform comprising:

• a plurality of first particles, each first particle comprising an insulating material and having a first mean particle size;
• and
• a plurality of second particles, each second particle comprising the insulating material and having a second mean particle size, wherein the second mean particle size is less than the first mean particle size, wherein:
• the insulation preform includes a first region having a first porosity and a second region having a second porosity less than the first porosity;
• the first region comprises more of the first particles of the plurality than the second region;
• and
• the second region comprises more of the second particles of the plurality than the first region.

An insulating component for an exhaust treatment component of a vehicle, the insulating component comprising:

• an outer wall;
• an inner wall that is at least partially disposed within the outer wall;
• an insulation preform disposed between the outer wall and the inner wall, the insulation preform comprising:
• a first region having a first density;
• and
• a second region having a second density that is greater than the first density, wherein:
• the first region of the insulation preform is disposed adjacent to a surface of the outer wall;
• the second region of the insulation preform is disposed adjacent to a surface of the inner wall;
• and
• the inner wall is adapted to be disposed around exhaust passageway of the exhaust treatment component.