The Open refining machine is a two-roller machine, the use of different rotational speed relative movement of two rollers to produce shear force to plastic. During the operation, the rubber material should be continuously punched into the triangle bag or curl. Mixer is the use of the internal design of the blade relative movement of the space generated by the regular contraction to produce shear force, without manual operation, save labor. The simple structure of the machine is low cost, but the labor intensity is big, the pollution is big, the injury to the worker's body is big. The mixer is more expensive, but it can be heated, and a pressurized mixer can be used to handle refractory materials. Labor intensity is low adaptability. The mixer is a kind of high strength gap mixing equipment developed on the basis of the open refining machine. Therefore, the emergence of the mixer is an important result of rubber machinery, and still is the typical important equipment of the plastic refining and mixing plant, which is still being developed and perfected.