Abstract: The insulating coating for an object such as a rocket motor casing is formed by wrapping a strip of insulating material upon the surface of a rotating mandrel. By means of this invention, it is possible to wrap a strip of malleable material such as rubber from an extruder onto a complex shape while exercising precise thickness control, thereby eliminating the need for machining the outer surface. The strip is run through a forming mill of unique construction which shapes the strip during the wrapping process to conform most precisely with the topography of the mandrel. The mill automatically varies both the taper and the width of the strip. The final wrapped product has a smooth outer surface that requires minimal finishing.

Abstract: The insulating coating for an object such as a rocket motor casing is formed by wrapping a strip of insulating material upon the surface of a rotating mandrel. By means of this invention, it is possible to wrap a strip of malleable material such as rubber from an extruder onto a complex shape while exercising precise thickness control, thereby eliminating the need for machining the outer surface. The strip is run through a forming mill of unique construction which shapes the strip during the wrapping process to conform most precisely with the topography of the mandrel. The mill automatically varies both the taper and the width of the strip. The final wrapped product has a smooth outer surface that requires minimal finishing.