A manufacturing method for an electrode paste by use of a twin-screw extrusion kneader for kneading a kneading material supplied to an internal space of a housing, the manufacturing method comprising:
- manufacturing the electrode paste by the twin-screw extrusion kneader by use of an active material, a binder, and a solvent as the kneading material,
- the twin-screw extrusion kneader used in the manufacturing method including:
- two rotating shafts provided side by side in the internal space;
- a rotational driving portion configured to rotationally drive the rotating shafts;
- paddles provided in the rotating shafts and configured to rotate along with the rotating shafts so as to knead the kneading material;
- and
- movable portions provided as members constituting a part of the housing, the part of the housing including an inner wall surface of the housing, the inner wall surface being opposed to radially outer peripheral surfaces of the paddles, wherein
- the paddles include a first paddle configured to apply a shear force to the kneading material and a second paddle configured to adjust a moving speed of the kneading material in a conveying direction of the kneading material in the internal space, the first paddle being provided on an upstream side of the second paddle in the conveying direction of the kneading material,
- the movable portions include an inner wall surface of the housing opposed to a radially outer peripheral surface of the first paddle, the movable portions being configured to move in a direction to approach the first paddle and in a direction to be distanced from the first paddle,
- the twin-screw extrusion kneader used in the manufacturing method includes position adjustment portions configured to perform position adjustment on the movable portions by moving the movable portions, and
- a viscosity index value output portion configured to output a viscosity index value indicative of a viscosity of the kneading material;
- and
- the position adjustment portions perform the position adjustment on the movable portions based on the viscosity index value output from the viscosity index value output portion,
- wherein
- the second paddle further comprises a first small paddle, a second small paddle, a first large paddle, and a second large paddle, wherein the first small paddle and the second small paddle are smaller than the first larger paddle and the second large paddle,
- the first small paddle and the first large paddle are placed in an order that is reverse to an order of placement of the second small paddle and the second large paddle in the conveying direction, and
- gaps formed between the first and the second large paddles and the inner wall surface of the housing are smaller than gaps formed between the first and the second small paddles and the inner wall surface of the housing.