Image Number 4 for United States Patent #4711009.
There is provided a process and apparatus for making, preferably continuously, a catalytic converter element or core especially adapted for the treatment of exhaust from an internal combustion engine, whether spark or compression ignited. The converter element may be a fan-folded or accordion folded thin metal strip or a spirally wound element which carries strongly adhered to the surface thereof a catalyst, e.g. a noble or precious metal catalyst such as platinum and/or palladium and/or rhodium. The metal strip entering the process is an aluminum coated ferritic ribbon between 0.001 and 0.003 inches thick, and 1 inch to 30 inches wide. The strip is preferably annealed and perforated at predetermined intervals. Thereafter, the strip is corrugated and given a washcoat of a refractory metal oxide which is calcined onto the surface. One or more precious metal catalysts are supplied and dried. The strip is desirably, albeit optionally, creased in a manner to enable it to be folded back and forth upon itself, severed to size, and folded to build a catalytic converter element. Final steps may include insertion of the catalytic converter element into a housing and affixing end caps to form a complete unit. This process provides a continuous low cost means for making catalytic converters.