MIXER FOR EXTRUSION

PURPOSE:To make the uniform mixing of highly viscous materials such as plastics, rubbers or the like possible by a structure wherein ridge lines or wall portions of cavities on a stator side and on a rotor side are made parallel to the shifting directions of a rotor and of a stator. CONSTITUTION:Groups 27 and 28 of cavities are produced by disposing trains 25 and 26 of cavities, which are formed by disposing cavities 23 and 24 in an array running in the circumferential direction (X X), in an array running in the direction (Y Y) of the axis center line on the inner peripheral surface of a stator 21 and on the outer peripheral surface of a rotor 22 excluding both the end parts of the rotor 22. Each cavity 23 or 24 is a parallelogram in the developed state with one pair of opposite wall portions 29 and 30, which run normal to the direction (Y Y) of the axis center line and have a space interval in the direction of the axis center line, and the outer pair of opposite wall portions 31 and 32, which respectively connect with the wall portions 29 and 30 and run obliquely in the same direction as each other to the direction (Y Y) and have a space interval in the circumferential direction (X X). Due to the constitution as described above, material pressed in the stator 21 is shifted from each cavity 23 or 24 to the cavity 24 or 23 overlapped to each other by means of the pressing-in force of extrusion members so as to be forcibly advanced in the extrusion direction Z. In addition, no force acting in the counter extrusion direction develops and no material is left in the cavities.