Extruder classification

Plastic extruders are divided into twin-screw extruders and single-screw extruders
The difference between the two extruders:
Single-screw machines and twin-screw machines: one has one screw, and the other has two screws. They are both driven by a motor. The power varies depending on the screw. The power of the 50-cone double is about 20kW, and the 65-cone is about 37kW. The output is related to the material and screw. The output of the 50-cone double is about 100-150kg/h, and the 65-cone double is about 200-280kg/h. The output of a single screw is only half.
Extruders can be divided into single-screw, twin-screw and multi-screw extruders according to the number of screws. Today, single-screw extruders are the most widely used and are suitable for the extrusion processing of general materials. The twin-screw extruder has the characteristics of less heat generated by friction, relatively uniform shearing of the material, large screw conveying capacity, relatively stable extrusion volume, long residence time of the material in the barrel, and uniform mixing.
The SJSZ series conical twin-screw extruder has the characteristics of forced extrusion, high quality, wide adaptability, long life, low shear rate, material is not easy to decompose, good mixing and plasticizing performance, direct molding of powder, etc., and the temperature is automatically controlled. Vacuum exhaust and other devices. Suitable for the production of tubes, plates, special-shaped materials and other products.
Single-screw extruders occupy an important position both as plasticizing and granulating machinery and as molding and processing machinery. In recent years, single-screw extruders have developed greatly. The large-scale single-screw extruder for granulation produced in Germany has a screw diameter of 700mm and an output of 36t/h.
The main sign of the development of single-screw extruders is the development of its key component - the screw. In recent years, people have conducted a lot of theoretical and experimental research on screws. Nowadays, there are nearly a hundred types of screws. Common ones include separation type, shear type, barrier type, split type and corrugated type.
From the perspective of single-screw development, although single-screw extruders are relatively complete, with the continuous development of polymer materials and plastic products, new screws and special single-screw extruders with more characteristics will emerge. Generally speaking, single-screw extruders are developing in the direction of high speed, high efficiency and specialization.
The twin-screw extruder has good feeding characteristics and is suitable for powder processing. It has better mixing, exhaust, reaction and self-cleaning functions than the single-screw extruder. It is characterized by processing plastics and blending with poor thermal stability. It shows its superiority even more when using materials. In recent years, foreign twin-screw extruders have developed greatly. Various forms of twin-screw extruders have been serialized and commercialized. There are also many manufacturers producing them. They are roughly classified as follows:
⑴According to the relative position of the two axes, it can be divided into parallel and conical;
⑵According to the meshing procedure of two screws, there are meshing type and non-meshing type;
⑶According to the rotation direction of the two screws, they can be divided into the same direction and the opposite direction, and the different directions can be divided into inward and outward; □
⑷According to the screw rotation speed, there are high speed and low speed;
⑸According to the structure of the screw and barrel, there are two types: integral and combined.
On the basis of twin-screw extruders, in order to make it easier to process blends with poor thermal stability, some manufacturers have developed multi-screw extruders such as planetary extruders.