Abstract: The apparatus includes an air temperature and humidity control chamber, a chopper room, strand choppers in the chopper room, a first controllable pitch fan having an inlet connected to the temperature and humidity control chamber and an outlet connected to the chopper room, a forming hood beneath the choppers, an endless conveyor chain beneath the forming hood, a chopped strand collecting chamber for collecting chopped strands which happen to pass through the conveyor chain, a suction chamber disposed beneath an upper flight of the conveyor chain and partitioned into a plurality of sections each having an inlet communicating with the forming hood through the conveyor chain and being provided with nozzle-forming downstream convergent baffle plates therein and an outlet communicating with the chopped strand collecting chamber through a duct having an adjustable damper therein securable in an adjusted position, a second controllable pitch fan having an inlet connected to the chopped strand collecting chamber and