Extruder according to the number of screw can be divided into single screw extruder, double screw extruder and multi screw extruder. The following Xiaobian to tell you about the difference between single screw extruder and twin screw extruder:
Single screw extruder and twin screw extruder, one is a screw, one is two screws, are driven by a motor. Power varies from screw to screw.
Now the single screw extruder is more widely used, suitable for extrusion processing of general materials. The twin-screw extruder has the characteristics of less heat generated by friction, more uniform shear of the material, larger screw conveying capacity, more stable extrusion capacity, long stay of the material in the barrel, and even mixing.
Single screw extruder occupies an important position both as plasticizing granulation machinery and forming processing machinery. In recent years, single screw extruder has had great development.
The double screw extruder has good feeding characteristics, suitable for powder processing, and has better mixing, exhaust, reaction and self-cleaning functions than the single screw extruder. It is characterized by the processing of plastics and blends with poor thermal stability, showing its superiority. In recent years, foreign twin-screw extruders have developed greatly. Various forms of twin-screw extruders have been serialized and commercialized, and there are many manufacturers.
As we all know, extrusion molding process is a polymer processing field in the production variety, change, high productivity, strong adaptability, wide use, the proportion of significant molding processing method. Extrusion molding is to make the polymer melt (or viscous fluid) in Yantai extruder screw extrusion action through a certain shape of the die molding, the product has a constant section shape of the continuous profile.
Extrusion molding process of extruder
Extrusion process is suitable for all polymer materials. Almost all thermoplastics can be formed, can also be used for thermosetting plastics, but only phenolic and other a few kinds of thermosetting plastics. The products of plastic extrusion include pipe, plate, bar, sheet, film, monofilament, cable coating, various profiles and composites of plastic and other materials. At present, about 50% of thermoplastic products are formed by extrusion. In addition, extrusion process is also commonly used in plastic coloring, mixing, plasticizing, granulation and plastic blending modification, based on extrusion molding, with blowing, stretching and other technology, and developed for extrusion blow molding and extrusion stretching molding manufacturing hollow blow molding and biaxial tensile film products. Extrusion molding is an important method in polymer molding.
Extrusion equipment has screw extruder and plunger extruder two categories, the former is continuous extrusion, the latter is intermittent extrusion, mainly used for high viscosity material molding, such as polytetrafluoroethylene, high molecular weight polyethylene. Screw extruder can be divided into single screw extruder and multi - screw extruder. Single screw extruder is the basic extruder in production. Twin-screw extruder has developed rapidly in recent years and its application is more and more extensive. At present, in the processing of PVC plastic door and window profiles, twin screw extruder has become the main production equipment, single screw extruder will be phased out. But in the extruder of other polymer extrusion processing, the single screw extruder is still dominant.