Single Screw Barrel Advantages And Disadvantages Of Extruder
The main body of the plastic extruder is the extruder, which consists of an extrusion system, a drive system and a heating and cooling system.
Here focuses on the extrusion system:
The extrusion system consists of screws, barrels, hoppers, heads, and molds, which are plasticized into a uniform melt through the extrusion system and are continuously extruded by the screw under the pressure established during this process.
(1) screw: the extruder is the most important components, it is directly related to the scope of application of extruder and productivity, made of high strength corrosion-resistant alloy steel.
(2) barrel: is a metal cylinder, generally with heat, high compressive strength, durable wear, corrosion-resistant alloy steel or alloy steel alloy made of composite steel pipe. Barrel and screw with the realization of the plastic crushing, softening, melting, plasticizing, exhaust and compaction, and to the forming system continuous uniform transport of rubber. The length of the general barrel is 15 to 30 times its diameter, so that the plastic is fully heated and fully plasticized to the principle.
(3) Hopper: The bottom of the hopper is equipped with a truncation device to adjust and cut the material. The side of the hopper is equipped with a viewing hole and a calibration metering device.
Advantages: single screw extruder design is simple, cheap, and thus widely used.
Disadvantages: (1) single screw extruder material delivery mainly rely on friction, so that its feeding performance is limited, powder, paste, glass fiber and inorganic fillers more difficult to join.
(2) When the head pressure is high, the countercurrent increases and the productivity is reduced.
(3) single-screw exhaust extruder material in the exhaust area of the surface update effect is small, so the exhaust effect is poor.
(4) single screw extruder is not suitable for certain processes, such as polymer coloring, thermosetting powder processing.
Extrusion in plastic processing, also known as extrusion, in the non-rubber extruder processing using hydraulic press pressure in the extrusion of the mold itself out. Refers to the material through the extruder barrel and the role of the screw, while by the thermoplastic, while the screw forward, continuous through the nose and made a variety of cross-section products or semi-finished products, a processing method.