Closed type rubber mixer, also known as kneading machine, is mainly used for mixing rubber and plastic. An internal mixer is a mechanical device that is equipped with a pair of rotors with specific shapes and relative rotations, and intermittently shapes and mixes polymer materials in a closed state with adjustable temperature and pressure. It mainly consists of an internal mixing chamber, rotor, rotor sealing device, feeding and pressing device, discharge device, transmission device, and machine base