A plasticizing device includes a drive motor, a rotor that is rotated by the drive motor and has a groove formed face with a groove formed therein, a barrel that is opposed to the groove formed face and has a communication hole, a heating portion that heats a material in a pellet form supplied between the groove and the barrel, and a control unit that controls the drive motor and the heating portion so as to plasticize the material supplied between the groove and the barrel and cause the material to flow out from the communication hole. The heating portion has a first heating portion and a second heating portion disposed closer to the communication hole than the first heating portion, and the barrel has a first region and a second region that is closer to the communication hole than the first region. The control unit individually controls the first heating portion and the second heating portion so that a temperature of the second region is higher than a temperature of the first region.

A plasticizing device includes: a drive motor; a rotating unit driven to rotate about a rotation axis by the drive motor and having an end surface perpendicular to the rotation axis and a lateral surface intersecting with the end surface; a barrel having a bottom surface facing the end surface of the rotating unit, and a heater; a case accommodating the rotating unit; and a material supply unit accommodating the material. At least one of the barrel and the case has a sidewall surface facing the lateral surface of the rotating unit and standing up along an outer circumference of the bottom surface of the barrel. At the bottom surface of the barrel, a communication hole through which the molten material flows out and a spiral groove part coupled to the communication hole are formed. The lateral surface of the rotating unit and the sidewall surface together define a supply space where the material is supplied from the material supply unit to the groove part.

There is provided with a screw that is inserted into a cylinder an inside of which a material is loaded, and is rotatably supported in both end portions on an upstream side and a downstream side, or in an end portion on the upstream side, in the cylinder; a first kneading blade including a plurality of first blades that are helically provided on the screw and send the material toward the downstream side with rotation of the screw; and a second kneading blade including a second blade that is helically provided on the screw and returns the material, which is sent toward the downstream side by the first kneading blade, toward the upstream side, the number of blades in the second blade being smaller than the number of blades in the first blade.

Mixing performance of resin material in the rotational direction of the screw is enhanced. Kneading disc 7 is fitted onto rotatable shaft 3 and is arranged in cylinder 2. Outer circumferential surface 8 of kneading disc 7 of the present invention that faces cylinder 2 has band portion 9 that extends between both ends 7a, 7b of kneading disc 7 in axial direction X of shaft 3 and that forms a minimum gap with cylinder 2. Band portion 9 includes at least one bent part 10.