Muffler packing method with injection of cartrided continuous filament fiberglass

A loose fiber packing material for a muffler of an internal combustion engine is temporarily confined in a transfer cartridge, having a shape which is substantially complementary or somewhat smaller than the muffler cavity. The transfer cartridge is adapted to receive a pushing device for discharging the loose fiber packing material from the transfer cartridge into the muffler cavity during manufacture of the muffler. The transfer cartridge allows loose fiber packing to be prepacked, shipped and directly transferred to a muffler cavity without the use of molding resins or packaging materials which would otherwise be inserted into the muffler along with the loose fiber packing material and burned away during initial use of the muffler, causing undesirable smoke and odor.