What are the characteristics of extruders?

There are two types of plastic extruders: twin-screw extruders and single-screw extruders. This article will introduce the characteristics of these two types of extruders and briefly describe the differences between them.

Here is the list of contents

• Characteristics of single-screw extruders

• Characteristics of twin-screw extruders

• Difference between single-screw and twin-screw machines

Characteristics of single-screw extruders

single-screw extruders occupy an important position both as plasticizing pelletizing machinery and molding processing machinery, and in recent years, single-screw extruders have seen great development. Germany produces a large pelletizing single-screw extruder with a screw diameter of 700mm and an output of 36t/h. The main sign of the development of the single-screw extruder lies in the development of its key component, the screw. In recent years, people have conducted a lot of theoretical and experimental research on the screw, now there are nearly 100 kinds of screws, common separation type, shear-type, barrier type, diversion type, and wave type.

From the single-screw development, although the single-screw extruder has been more perfect, with the continuous development of polymer materials and plastic products, there will be more characteristics of the new screw and special single-screw extruder. In general, single-screw extruders are developing towards high speed, high efficiency, and specialization.

Characteristics of twin-screw extruders

SJSZ series conical twin-screw extruder has the features of forced extrusion, high quality, wide adaptability, long life, small shear rate, the material is not easy to decompose, good mixing and plasticizing performance, direct molding of powder, temperature self-control, vacuum exhaust and other devices. It is suitable for the production of pipes, plates, shaped materials, and other products.

The twin-screw extruder has good feeding characteristics, is suitable for powder processing, and has better mixing, exhaust, reaction, and self-cleaning functions than the single-screw extruder, characterized by the poor thermal stability of the processing of plastics and co-mingled materials show its superiority. In recent years, foreign twin-screw extruder has been a great development, various forms of twin-screw extruder have been serialized and commercialized, the production of manufacturers are more, roughly classified as follows.

According to the relative position of the two axes, there are parallel and conical.

by the two screw engagement procedure, there is engaged and non-engaged type.

by the direction of rotation of the two screws, there are the same direction and anisotropy, in the anisotropy and inward, outward.

by the speed of rotation of the screw, there are high-speed and low-speed.

According to the structure of the screw and the barrel, there is the whole and combined.

On the basis of twin-screw extruders, some manufacturers have developed multi-screw extruders such as planetary extruders in order to process the co-mingled material with poor thermal stability more easily.

Difference between single-screw and twin-screw machines

The main difference between the two is the difference in structure, one is a screw, one is two screws. Both are driven by a single motor, the power varies from screw to screw. 50 cone twin has a power of about 20kW and 65 has a power of about 37kW. the output is related to the screw, the 50 cone twin has an output of about 100-150kg/h and the 65 cone twin has an output of 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 their number of screws. Today, single-screw extruders are the most widely used and are suitable for general material extrusion processing. The twin-screw extruder has the characteristics of less heat generated by friction, more uniform shearing of the material, a larger conveying capacity of the screw, more stable extrusion volume, long stay of the material in the barrel, and uniform mixing.

Zhangjiagang Chenxing Machinery Co., Ltd has many years of experience in the production of equipment, doing the industry model, creating first-class products of plastic machinery as the corporate purpose, integrity first, service first as the business purpose, to provide more detailed technical support and service for domestic and foreign customers and. We produce high-quality extruder equipment for extruding thermoplastics such as soft polyvinyl chloride (PVC) and polystyrene (PE). Together with appropriate auxiliary machines (including leads for molding machines), we can produce a wide range of plastic products such as film tubes, sheets, woven tapes, strips, and pellets. If you are interested in our products, welcome to contact us!