Patent ID: 8186058

Claim:
A Method of making a molded preform for use in an exhaust system component of an exhaust system of an internal combustion engine, the exhaust system component comprising two opposing metal walls defining a gap therebetween, with the molded preform being disposed in the gap, and a space through which exhaust gas may flow when the exhaust system component is used in an exhaust system of an internal combustion engine, said method comprising: mixing water, a binder and chopped magnesium aluminium silicate glass fibers to form a slurry of non-intumescent insulation material; providing a mold constructed to form a molded preform comprising the insulation material and being dimensioned so as to be positionable within the gap between the two opposing walls of the exhaust system component, with the mold having a screen through which water from the slurry is removed; and processing the slurry to form the molded preform, said processing comprising disposing the slurry into the mold and removing the water from the slurry through the screen so as to form the molded perform, wherein the removal of the water through the screen forms the molded preform into either (a) a tubular shape suitable for use in a double-walled exhaust pipe of an exhaust system or (b) an end cone preform having a three dimensional conical shape with dimensions suitable for being inserted into and insulating an end cone region of a pollution control device, and the end cone preform maintains its three dimensional conical shape under the force of gravity after having been molded.