The present invention relates to a method of producing a powder coating material containing a fluororesin and a non-fluororesin. The method of producing a powder coating material includes kneading a raw material containing the fluororesin and the non-fluororesin with a kneading extruder equipped with a screw having a kneading zone, wherein a ratio of a length L.sub.K of the kneading zone to an effective length L.sub.S of the screw (L.sub.K/L.sub.S×100) is 21.0 to 50.0%.

The present invention relates to a method of producing a powder coating material containing a fluororesin and a non-fluororesin. The method of producing a powder coating material includes kneading a raw material containing the fluororesin and the non-fluororesin with a kneading extruder equipped with a screw having a kneading zone, wherein a ratio of a length L.sub.K of the kneading zone to an effective length L.sub.S of the screw (L.sub.K/L.sub.S×100) is 21.0 to 50.0%.

A kneading apparatus includes a processor, and a extruder. The extruder includes a screw. The screw includes a screw main body. A conveyance portion, a barrier portion, and a path are provided at places of the screw main body. In at least one of the places, the path is provided inside the screw main body, and includes an entrance and an exit. The raw materials, pressure on which is increased by the barrier portion, flow in from the entrance. The raw materials flowing in from the entrance flow through the path toward the exit. The exit is positioned to be remote from the entrance in an axial direction.

A kneading apparatus includes a processor, and a extruder. The extruder includes a screw. The screw includes a screw main body. A conveyance portion, a barrier portion, and a path are provided at places of the screw main body. In at least one of the places, the path is provided inside the screw main body, and includes an entrance and an exit. The raw materials, pressure on which is increased by the barrier portion, flow in from the entrance. The raw materials flowing in from the entrance flow through the path toward the exit. The exit is positioned to be remote from the entrance in an axial direction.

An extruder is provided with: a screw rotationally driven about the axis by a first motor; a barrel having a screw hole into which the screw is inserted and a de-airing port configured to discharge air inside the screw hole; a filter configured such that a part thereof faces the de-airing port of the barrel; and a filter-driving mechanism configured to move the filter to shift the part of the filter facing the de-airing port.

A method for producing a resin composition of the present invention is a method for producing a resin composition, the method including a step of obtaining a resin composition by heating and melt-kneading a mixture containing a particulate nucleating agent in which D.sub.50 is equal to or more than 0.1 μm and equal to or less than 300 μm and a thermoplastic resin using a twin screw extruder (100) including, inside a cylinder (10), a screw (50) having kneading discs (60), in which the step of obtaining a resin composition includes an extrusion step of extruding the mixture supplied into the twin screw extruder (100) in an ejection direction under kneading conditions in which X and Y satisfy 4.0≤X in a range of 6.0×10.sup.3≤Y≤7.0×10.sup.4 when a volume-based ejection amount is denoted by X (10.sup.−6.Math.kg.Math.h.sup.−1.Math.mm.sup.−3), and a strain rate is denoted by Y (min.sup.−1).

A method for producing a nitrile rubber, includes recovering a nitrile rubber from a latex of nitrile rubber by continuously feeding the latex of nitrile rubber and a coagulant into an extruder including a screw disposed inside a barrel to be rotatably driven, wherein the latex of nitrile rubber fed into the extruder contains 0.1 to 3 parts by weight of a hindered phenol-based antiaging agent having a molecular weight of 300 to 3000 relative to 100 parts by weight of the nitrile rubber.

Disclosed is a recycling apparatus for a cross-linked polyethylene resin using a twin screw extruder. The recycling apparatus for a cross-linked polyethylene resin using a twin screw extruder according to an embodiment of the present disclosure includes: a raw material supply unit configured to supply a raw material that is a cross-linked polyethylene resin; and a twin screw extruder configured to receive the raw material from the raw material supply unit, the twin screw extruder including a cylinder and a twin screw installed inside the cylinder to rotate in the same direction, the twin screw extruder being configured to de-crosslink and recycle the raw material under a de-crosslinking reaction temperature and reaction pressure atmosphere while continuously transporting the raw material along the twin screw by the rotation of the twin screw.

A kneading apparatus includes a processor, and a extruder. The extruder includes a screw. The screw includes a screw main body. A conveyance portion, a barrier portion, and a path are provided at places of the screw main body. In at least one of the places, the path is provided inside the screw main body, and includes an entrance and an exit. The raw materials, pressure on which is increased by the barrier portion, flow in from the entrance. The raw materials flowing in from the entrance flow through the path toward the exit. The exit is positioned to be remote from the entrance in an axial direction.

A kneading apparatus includes a processor, and a extruder. The extruder includes a screw. The screw includes a screw main body. A conveyance portion, a barrier portion, and a path are provided at places of the screw main body. In at least one of the places, the path is provided inside the screw main body, and includes an entrance and an exit. The raw materials, pressure on which is increased by the barrier portion, flow in from the entrance. The raw materials flowing in from the entrance flow through the path toward the exit. The exit is positioned to be remote from the entrance in an axial direction.