Sheet molding compound production method and fiber mat deposition device

A method of manufacturing a sheet molding compound using a fiber mat deposition apparatus comprising a chopping part and a dispersing part disposed below the chopping part, the method comprising:

• drawing out a carrier film from a roll to travel on a conveyance path such that a surface of the carrier film is horizontal;
• cutting a continuous carbon fiber bundle into short carbon fiber bundles in the chopping part of the fiber mat deposition apparatus disposed above the conveyance path;
• allowing the short carbon fiber bundles to fall onto the carrier film traveling on the conveyance path while dispersing the short carbon fiber bundles in the dispersing part of the fiber mat deposition apparatus using a dispersing roll having a rotation axis parallel to a T direction to form a carbon fiber mat on the carrier film;
• impregnating the carbon fiber mat with a thermosetting resin composition to obtain a resin-impregnated carbon fiber mat;
• and
• concurrently with the forming the carbon fiber mat, removing fiber dust generated from the short carbon fiber bundles due to contact with the dispersing roll using one or more dust collectors, which optionally includes a cyclone dust collector,
• wherein the dispersing part of the fiber mat deposition apparatus is disposed on an inside of an enclosure of the fiber mat deposition apparatus,
• the one or more dust collectors is connected to:
• a suction nozzle disposed on the inside of the enclosure;
• or a suction hood disposed above the chopping part,
• the suction nozzle has an opening having a width W, and
• the width W is 50% or more of an inner dimension of the enclosure.