Single screw extruder is the most widely used general extruder in the extruder product series. Its structural characteristics are: the extrusion system of the extruder is composed of a screw and a barrel. The single-screw extruder has a wide range of uses. For the extrusion of different thermoplastics, as long as the structure of the screw is changed, it can complete the production of extruded products with different raw materials. The structure of Single screw extruder mainly includes transmission system, compression molding system, feeding system, heating and cooling system and electric control system.

(1) Main components of compression molding system
The compression molding system of the extruder is the main part of the extruder equipment. Its function is to squeeze and heat the raw materials from the solid state to the plasticized molten state, and then extrude them from the manifold (also called the perforated plate) at the front of the barrel at equal amounts and equal pressure, and then enter the molding. Product mold.
(2) The main components of the transmission system The transmission system of the Single screw extruder is mainly composed of components such as electric motors, gear reducers, V-belt transmissions or couplings. The function of the transmission system is mainly to drive the screw to rotate within a certain speed range. According to the requirements of the production process, ensure that the screw rotates evenly and stably under a certain torque force to complete the plastic melting and plasticization and be pushed out of the barrel. Transport work.
The part structure of the transmission system that supports the rotation of the screw and bears the axial force of the screw is a part that is prone to failure in the production of the extruder. The main cause of the failure is that the raw materials are mixed with metal block-like hard objects, which jam the screw in the barrel, or the low temperature of the raw materials in the extrusion production is affected, which causes the rolling bearing of the supporting shaft to be damaged.
(3) Heating and cooling system When the Single screw extruder starts extrusion production, heating the barrel is to provide a certain amount of heat to the plastic in the barrel to promote the plasticization of the plastic under the action of the screw. The cooling of the barrel is to control the temperature of the plastic in the barrel due to the extruding, friction and other conditions of the screw to generate heat and increase the temperature, limiting the barrel temperature within a certain process range to ensure smooth extrusion production.
(4)Quick screen changer
In the extrusion plasticization system of a single-screw extruder, a perforated plate and a filter screen are generally provided on the barrel at the front end of the screw. The filter screens and perforated plates of different meshes can be replaced according to the needs of the products; some products can also be extruded without perforated plates and filters. At present, when the filter screen is used for extruded products, there is a quick screen changing device. When the screen needs to be changed, the sliding plate is driven by the hydraulic cylinder to quickly move the sliding plate to complete the replacement of the old and new screen positions. At this time, some molten material will be extruded from the gap of the sliding plate and cooled and solidified in the gap to form a layer of about 0.1mm thick, which plays a role of sealing.
(5) Control system The control system in the Single screw extruder equipment is mainly used to control the process parameters such as the screw speed, the heating temperature of each part and the pressure of the plasticizing material melt during the production process of the extruder. At present, the control system of extruder mostly adopts instrument control; PLC programmable control system is also beginning to be applied. Comparing the two control systems, the PLC programmable control system is more suitable for the intelligent, automated and digital control of the extrusion process of the extruder.
The above is the relevant introduction about the "Single screw extruder structure and main parts". Through the above introduction, we can understand that the single screw extruder has a relatively simple structure, low cost, easy to use and operate, and maintenance and overhaul of the equipment. It is also more convenient. Therefore, the single-screw extruder is the first choice for many manufacturers of plastic products.