A Machine Used for Plasticizing and Extrusion
The planetary screw extruder is a planetary screw structure in the middle of the screw in the extruder (i.e. plasticized section) or the whole screw (only the feeding part of the feeding section is not a planetary screw). When working with the center screw as the active screw, its outer circle has a number of small diameter screw and its meshing rotation, these small diameter screw can rotate and can rotate around the center of the screw, this is due to the meshing with small screw’s periphery and inner coat with spiral teeth. The jacket is also a barrel and is bolted to the front and rear barrels. The thread section of the screw is involute tooth shape, and the screw is multi-thread.
The combination of three parts, the central screw, the planetary small diameter screw and the outer cylinder with threaded teeth in the figure, becomes the mixing and plasticizing mechanism of the planetary screw. Their thread distance, thread depth and tooth meshing angle of vertical section are equal; the dividing circle distance from the coat spiral tooth is also equal; the center distance between each planetary screw is equal and larger than the diameter of the planetary screw to avoid interference during meshing transmission. These data are the working parameters necessary to ensure the normal meshing and rotation of this set of planetary screws.
The way of planetary screw mixing plasticizing raw material is: the feeding section thread pushed to the planetary section of raw material, in the rear part of the screw feed continuous strong push, to the front of the screw head extrusion move, from the center screw and barrel between the inner screw teeth and its meshing between the planetary small diameter screw teeth through; due to the constant rotation of each screw in the planetary screw, the raw materials are subjected to strong extrusion, rolling and shearing forces in the intermeshing and rotating thread teeth gap, so that the raw materials are constantly turned and mixed in this section, finally into a molten state, uniformly plasticized, and gradually pushed to the front section of the screw and extruded from the head.