Plasticizing unit supplying a prescribed amount of fiber material pieces to heating cylinder using a vacuum or blower fiber transfer device

A plasticizing unit comprising:

• a heating cylinder;
• a screw that is received rotatably inside the heating cylinder;
• a resin supply hole and a fiber supply hole that are opened in the heating cylinder;
• and a fiber supply device that supplies a fiber material into the heating cylinder through the fiber supply hole;
• wherein:
• the fiber supply device includes at least one reel on which a long fiber material is wound, a cutting section by which the long fiber material pulled out from the reel is cut off into a prescribed length, and a pressure-feeding section by which fiber material pieces each cut in the prescribed length by the cutting section are pressed into the heating cylinder through the fiber supply hole;
• the pressure-feeding section has a pressing cylinder that is attached to the heating cylinder so that one end of the pressing cylinder can communicate with the fiber supply hole, a pressing piston that is received slidably inside the pressing cylinder, a fiber supply pipe through which a head chamber of the pressing cylinder and the cutting section can communicate with each other, and a fiber transfer device by which the fiber material pieces staying in the cutting section and inside the fiber supply pipe are transferred into the head chamber of the pressing cylinder;
• and
• the fiber transfer device includes a vacuum device that is coupled to the pressing cylinder to suck the fiber material pieces staying in the cutting section and inside the fiber supply pipe into the head chamber of the pressing cylinder,
• an air exhaust pipe communicating with the vacuum device is provided on a rod chamber side of the pressing cylinder, and the vacuum device sucks the fiber material pieces staying in the cutting section and inside the fiber supply pipe through a gap between an inner surface of the pressing cylinder and an outer surface of the pressing piston, and
• an air exhaust pipe communicating with the vacuum device is provided on a head chamber side of the pressing cylinder, and a filter for preventing the fiber from being diffused is provided in the air exhaust pipe.